21151468 has 48 divisors (see below), whose sum is σ = 42928704. Its totient is φ = 9031680.

The previous prime is 21151433. The next prime is 21151483. The reversal of 21151468 is 86415112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62596 + ... + 62932.

It is an arithmetic number, because the mean of its divisors is an integer number (894348).

Almost surely, 2^21151468 is an apocalyptic number.

It is an amenable number.

21151468 is an abundant number, since it is smaller than the sum of its proper divisors (21777236).

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

21151468 is a wasteful number, since it uses less digits than its factorization.

21151468 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 440 counting only the distinct ones).

The product of its digits is 1920, while the sum is 28.

The square root of 21151468 is about 4599.0725151926. The cubic root of 21151468 is about 276.5541446591.

The spelling of 21151468 in words is "twenty-one million, one hundred fifty-one thousand, four hundred sixty-eight".