40021980 has 48 divisors (see below), whose sum is σ = 117962880. Its totient is φ = 10110528.

The previous prime is 40021973. The next prime is 40021997. The reversal of 40021980 is 8912004.

It is a self number, because there is not a number n which added to its sum of digits gives 40021980.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16414 + ... + 18693.

It is an arithmetic number, because the mean of its divisors is an integer number (2457560).

Almost surely, 2^40021980 is an apocalyptic number.

It is an amenable number.

40021980 is an abundant number, since it is smaller than the sum of its proper divisors (77940900).

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

40021980 is a wasteful number, since it uses less digits than its factorization.

40021980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35138 (or 35136 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 40021980 is about 6326.2927532640. The cubic root of 40021980 is about 342.0578199837.

Adding to 40021980 its sum of digits (24), we get a palindrome (40022004).

Adding to 40021980 its reverse (8912004), we get a palindrome (48933984).

The spelling of 40021980 in words is "forty million, twenty-one thousand, nine hundred eighty".