21710394 has 24 divisors (see below), whose sum is σ = 49806900. Its totient is φ = 6811008.

The previous prime is 21710389. The next prime is 21710417. The reversal of 21710394 is 49301712.

It can be written as a sum of positive squares in 2 ways, for example, as 20115225 + 1595169 = 4485^2 + 1263^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35169 + ... + 35780.

Almost surely, 2^21710394 is an apocalyptic number.

21710394 is an abundant number, since it is smaller than the sum of its proper divisors (28096506).

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

21710394 is a wasteful number, since it uses less digits than its factorization.

21710394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70974 (or 70971 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21710394 is about 4659.4413828269. The cubic root of 21710394 is about 278.9689717681.

The spelling of 21710394 in words is "twenty-one million, seven hundred ten thousand, three hundred ninety-four".