21521862 has 20 divisors (see below), whose sum is σ = 48225276. Its totient is φ = 7173900.

The previous prime is 21521849. The next prime is 21521893. The reversal of 21521862 is 26812512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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 9 ways as a sum of consecutive naturals, for example, 66264 + ... + 66587.

Almost surely, 2^21521862 is an apocalyptic number.

21521862 is an abundant number, since it is smaller than the sum of its proper divisors (26703414).

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

21521862 is a wasteful number, since it uses less digits than its factorization.

21521862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132865 (or 132856 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 21521862 is about 4639.1660888569. The cubic root of 21521862 is about 278.1591053072.

The spelling of 21521862 in words is "twenty-one million, five hundred twenty-one thousand, eight hundred sixty-two".