21156026 has 8 divisors (see below), whose sum is σ = 31769760. Its totient is φ = 10566108.

The previous prime is 21156019. The next prime is 21156029. The reversal of 21156026 is 62065112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21156026² = 895154872225352, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21155992 and 21156010.

It is not an unprimeable number, because it can be changed into a prime (21156029) 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 3 ways as a sum of consecutive naturals, for example, 3536 + ... + 7403.

It is an arithmetic number, because the mean of its divisors is an integer number (3971220).

Almost surely, 2^21156026 is an apocalyptic number.

21156026 is a deficient number, since it is larger than the sum of its proper divisors (10613734).

21156026 is a wasteful number, since it uses less digits than its factorization.

21156026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11908.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21156026 is about 4599.5680231952. The cubic root of 21156026 is about 276.5740084223.

The spelling of 21156026 in words is "twenty-one million, one hundred fifty-six thousand, twenty-six".