21170612 has 6 divisors (see below), whose sum is σ = 37048578. Its totient is φ = 10585304.

The previous prime is 21170587. The next prime is 21170629. The reversal of 21170612 is 21607112.

It can be written as a sum of positive squares in only one way, i.e., 12432676 + 8737936 = 3526^2 + 2956^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2646323 + ... + 2646330.

It is an arithmetic number, because the mean of its divisors is an integer number (6174763).

Almost surely, 2^21170612 is an apocalyptic number.

It is an amenable number.

21170612 is a deficient number, since it is larger than the sum of its proper divisors (15877966).

21170612 is a wasteful number, since it uses less digits than its factorization.

21170612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5292657 (or 5292655 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 21170612 is about 4601.1533336762. The cubic root of 21170612 is about 276.6375550408.

Adding to 21170612 its reverse (21607112), we get a palindrome (42777724).

The spelling of 21170612 in words is "twenty-one million, one hundred seventy thousand, six hundred twelve".