40809090 has 64 divisors (see below), whose sum is σ = 115810560. Its totient is φ = 9004800.

The previous prime is 40809073. The next prime is 40809091. The reversal of 40809090 is 9090804.

It is a Harshad number since it is a multiple of its sum of digits (30).

40809090 is a modest number, since divided by 9090 gives 4080 as remainder.

It is not an unprimeable number, because it can be changed into a prime (40809091) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2740 + ... + 9440.

It is an arithmetic number, because the mean of its divisors is an integer number (1809540).

Almost surely, 2^40809090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40809090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57905280).

40809090 is an abundant number, since it is smaller than the sum of its proper divisors (75001470).

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

40809090 is a wasteful number, since it uses less digits than its factorization.

40809090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6747.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 40809090 is about 6388.1992767915. The cubic root of 40809090 is about 344.2856886237.

Adding to 40809090 its reverse (9090804), we get a palindrome (49899894).

The spelling of 40809090 in words is "forty million, eight hundred nine thousand, ninety".