21956499 has 12 divisors (see below), whose sum is σ = 31785000. Its totient is φ = 14605344.

The previous prime is 21956479. The next prime is 21956527. The reversal of 21956499 is 99465912.

It is not a de Polignac number, because 21956499 - 2⁸ = 21956243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21956479) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2047 + ... + 6935.

It is an arithmetic number, because the mean of its divisors is an integer number (2648750).

Almost surely, 2^21956499 is an apocalyptic number.

21956499 is a deficient number, since it is larger than the sum of its proper divisors (9828501).

21956499 is a wasteful number, since it uses less digits than its factorization.

21956499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5394 (or 5391 counting only the distinct ones).

The product of its digits is 174960, while the sum is 45.

The square root of 21956499 is about 4685.7762430573. The cubic root of 21956499 is about 280.0191270947.

The spelling of 21956499 in words is "twenty-one million, nine hundred fifty-six thousand, four hundred ninety-nine".