21373570 has 16 divisors (see below), whose sum is σ = 39714048. Its totient is φ = 8273520.

The previous prime is 21373559. The next prime is 21373577. The reversal of 21373570 is 7537312.

It is not an unprimeable number, because it can be changed into a prime (21373577) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34164 + ... + 34783.

It is an arithmetic number, because the mean of its divisors is an integer number (2482128).

Almost surely, 2^21373570 is an apocalyptic number.

21373570 is a deficient number, since it is larger than the sum of its proper divisors (18340478).

21373570 is a wasteful number, since it uses less digits than its factorization.

21373570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68985.

The product of its (nonzero) digits is 4410, while the sum is 28.

The square root of 21373570 is about 4623.1558485519. The cubic root of 21373570 is about 277.5187661470.

The spelling of 21373570 in words is "twenty-one million, three hundred seventy-three thousand, five hundred seventy".