20916440 has 32 divisors (see below), whose sum is σ = 47196000. Its totient is φ = 8342784.

The previous prime is 20916439. The next prime is 20916479. The reversal of 20916440 is 4461902.

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22301 + ... + 23219.

It is an arithmetic number, because the mean of its divisors is an integer number (1474875).

Almost surely, 2^20916440 is an apocalyptic number.

20916440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20916440 is an abundant number, since it is smaller than the sum of its proper divisors (26279560).

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

20916440 is a wasteful number, since it uses less digits than its factorization.

20916440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1499 (or 1495 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 20916440 is about 4573.4494640260. The cubic root of 20916440 is about 275.5260015226.

The spelling of 20916440 in words is "twenty million, nine hundred sixteen thousand, four hundred forty".