21489704 has 8 divisors (see below), whose sum is σ = 40293210. Its totient is φ = 10744848.

The previous prime is 21489701. The next prime is 21489707. The reversal of 21489704 is 40798412.

It is an interprime number because it is at equal distance from previous prime (21489701) and next prime (21489707).

It can be written as a sum of positive squares in only one way, i.e., 21141604 + 348100 = 4598^2 + 590^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21489701) by changing a digit.

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 as a sum of consecutive naturals, namely, 1343099 + ... + 1343114.

Almost surely, 2^21489704 is an apocalyptic number.

It is an amenable number.

21489704 is a deficient number, since it is larger than the sum of its proper divisors (18803506).

21489704 is a wasteful number, since it uses less digits than its factorization.

21489704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2686219 (or 2686215 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 21489704 is about 4635.6988685634. The cubic root of 21489704 is about 278.0204943227.

The spelling of 21489704 in words is "twenty-one million, four hundred eighty-nine thousand, seven hundred four".