40781000 has 64 divisors (see below), whose sum is σ = 102800880. Its totient is φ = 15052800.

The previous prime is 40780969. The next prime is 40781003. The reversal of 40781000 is 18704.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 5044516 + 35736484 = 2246^2 + 5978^2 .

It is a super-2 number, since 2×40781000² = 3326179922000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (40781003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11432 + ... + 14568.

Almost surely, 2^40781000 is an apocalyptic number.

40781000 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40781000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51400440).

40781000 is an abundant number, since it is smaller than the sum of its proper divisors (62019880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

40781000 is a wasteful number, since it uses less digits than its factorization.

40781000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3171 (or 3157 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 40781000 is about 6386.0003131851. Note that the first 3 decimals coincide. The cubic root of 40781000 is about 344.2066767763.

Adding to 40781000 its reverse (18704), we get a palindrome (40799704).

The spelling of 40781000 in words is "forty million, seven hundred eighty-one thousand".