21149704 has 8 divisors (see below), whose sum is σ = 39655710. Its totient is φ = 10574848.

The previous prime is 21149699. The next prime is 21149731. The reversal of 21149704 is 40794112.

It can be written as a sum of positive squares in only one way, i.e., 21141604 + 8100 = 4598^2 + 90^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321849 + ... + 1321864.

Almost surely, 2^21149704 is an apocalyptic number.

It is an amenable number.

21149704 is a deficient number, since it is larger than the sum of its proper divisors (18506006).

21149704 is a wasteful number, since it uses less digits than its factorization.

21149704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2643719 (or 2643715 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21149704 is about 4598.8807333959. The cubic root of 21149704 is about 276.5464563815.

The spelling of 21149704 in words is "twenty-one million, one hundred forty-nine thousand, seven hundred four".