21054956 has 24 divisors (see below), whose sum is σ = 39948720. Its totient is φ = 9652032.

The previous prime is 21054953. The next prime is 21054967. The reversal of 21054956 is 65945012.

It is a happy number.

It is a super-2 number, since 2×21054956² = 886622344323872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21054953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6875 + ... + 9453.

It is an arithmetic number, because the mean of its divisors is an integer number (1664530).

Almost surely, 2^21054956 is an apocalyptic number.

21054956 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21054956 is a deficient number, since it is larger than the sum of its proper divisors (18893764).

21054956 is a wasteful number, since it uses less digits than its factorization.

21054956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2753 (or 2751 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 21054956 is about 4588.5679683317. The cubic root of 21054956 is about 276.1328737789.

Adding to 21054956 its reverse (65945012), we get a palindrome (86999968).

The spelling of 21054956 in words is "twenty-one million, fifty-four thousand, nine hundred fifty-six".