21156654 has 16 divisors (see below), whose sum is σ = 42392448. Its totient is φ = 7039032.

The previous prime is 21156647. The next prime is 21156661. The reversal of 21156654 is 45665112.

It is an interprime number because it is at equal distance from previous prime (21156647) and next prime (21156661).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 519 + ... + 6525.

It is an arithmetic number, because the mean of its divisors is an integer number (2649528).

Almost surely, 2^21156654 is an apocalyptic number.

21156654 is an abundant number, since it is smaller than the sum of its proper divisors (21235794).

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

21156654 is a wasteful number, since it uses less digits than its factorization.

21156654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6599.

The product of its digits is 7200, while the sum is 30.

The square root of 21156654 is about 4599.6362899690. The cubic root of 21156654 is about 276.5767450226.

It can be divided in two parts, 211 and 56654, that added together give a palindrome (56865).

The spelling of 21156654 in words is "twenty-one million, one hundred fifty-six thousand, six hundred fifty-four".