21970402 has 4 divisors (see below), whose sum is σ = 32955606. Its totient is φ = 10985200.

The previous prime is 21970397. The next prime is 21970427. The reversal of 21970402 is 20407912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20784481 + 1185921 = 4559^2 + 1089^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5492599 + ... + 5492602.

Almost surely, 2^21970402 is an apocalyptic number.

21970402 is a deficient number, since it is larger than the sum of its proper divisors (10985204).

21970402 is a wasteful number, since it uses less digits than its factorization.

21970402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10985203.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21970402 is about 4687.2595404991. The cubic root of 21970402 is about 280.0782179437.

The spelling of 21970402 in words is "twenty-one million, nine hundred seventy thousand, four hundred two".