21246642 has 12 divisors (see below), whose sum is σ = 46034430. Its totient is φ = 7082208.

The previous prime is 21246637. The next prime is 21246683. The reversal of 21246642 is 24664212.

21246642 is a `hidden beast` number, since 2 + 12 + 4 + 6 + 642 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20875761 + 370881 = 4569^2 + 609^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 590167 + ... + 590202.

Almost surely, 2^21246642 is an apocalyptic number.

21246642 is an abundant number, since it is smaller than the sum of its proper divisors (24787788).

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

21246642 is a wasteful number, since it uses less digits than its factorization.

21246642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1180377 (or 1180374 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 21246642 is about 4609.4079880176. The cubic root of 21246642 is about 276.9683221300.

The spelling of 21246642 in words is "twenty-one million, two hundred forty-six thousand, six hundred forty-two".