21910156 has 6 divisors (see below), whose sum is σ = 38342780. Its totient is φ = 10955076.

The previous prime is 21910123. The next prime is 21910157. The reversal of 21910156 is 65101912.

It is a self number, because there is not a number n which added to its sum of digits gives 21910156.

It is not an unprimeable number, because it can be changed into a prime (21910157) 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 as a sum of consecutive naturals, namely, 2738766 + ... + 2738773.

Almost surely, 2^21910156 is an apocalyptic number.

It is an amenable number.

21910156 is a deficient number, since it is larger than the sum of its proper divisors (16432624).

21910156 is a wasteful number, since it uses less digits than its factorization.

21910156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5477543 (or 5477541 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 21910156 is about 4680.8285591335. The cubic root of 21910156 is about 279.8219786765.

The spelling of 21910156 in words is "twenty-one million, nine hundred ten thousand, one hundred fifty-six".