21080956 has 36 divisors (see below), whose sum is σ = 41967912. Its totient is φ = 9209376.

The previous prime is 21080933. The next prime is 21080963. The reversal of 21080956 is 65908012.

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 11 ways as a sum of consecutive naturals, for example, 18211 + ... + 19333.

Almost surely, 2^21080956 is an apocalyptic number.

21080956 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21080956 is a deficient number, since it is larger than the sum of its proper divisors (20886956).

21080956 is a wasteful number, since it uses less digits than its factorization.

21080956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1178 (or 1157 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 21080956 is about 4591.4002221545. The cubic root of 21080956 is about 276.2464891755.

Adding to 21080956 its reverse (65908012), we get a palindrome (86988968).

The spelling of 21080956 in words is "twenty-one million, eighty thousand, nine hundred fifty-six".