21542562 has 12 divisors (see below), whose sum is σ = 46675590. Its totient is φ = 7180848.

The previous prime is 21542537. The next prime is 21542579. The reversal of 21542562 is 26524512.

It can be written as a sum of positive squares in only one way, i.e., 21427641 + 114921 = 4629^2 + 339^2 .

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 5 ways as a sum of consecutive naturals, for example, 598387 + ... + 598422.

Almost surely, 2^21542562 is an apocalyptic number.

21542562 is an abundant number, since it is smaller than the sum of its proper divisors (25133028).

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

21542562 is a wasteful number, since it uses less digits than its factorization.

21542562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196817 (or 1196814 counting only the distinct ones).

The product of its digits is 4800, while the sum is 27.

The square root of 21542562 is about 4641.3965570720. The cubic root of 21542562 is about 278.2482557171.

It can be divided in two parts, 2 and 1542562, that added together give a square (1542564 = 1242²).

The spelling of 21542562 in words is "twenty-one million, five hundred forty-two thousand, five hundred sixty-two".