40051581 has 16 divisors (see below), whose sum is σ = 55407360. Its totient is φ = 25704000.

The previous prime is 40051577. The next prime is 40051631. The reversal of 40051581 is 18515004.

It is not a de Polignac number, because 40051581 - 2² = 40051577 is a prime.

It is a super-2 number, since 2×40051581² = 3208258281199122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40051511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52956 + ... + 53706.

It is an arithmetic number, because the mean of its divisors is an integer number (3462960).

Almost surely, 2^40051581 is an apocalyptic number.

It is an amenable number.

40051581 is a deficient number, since it is larger than the sum of its proper divisors (15355779).

40051581 is a wasteful number, since it uses less digits than its factorization.

40051581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1396.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 40051581 is about 6328.6318426655. The cubic root of 40051581 is about 342.1421299744.

Adding to 40051581 its reverse (18515004), we get a palindrome (58566585).

The spelling of 40051581 in words is "forty million, fifty-one thousand, five hundred eighty-one".