21370156 has 12 divisors (see below), whose sum is σ = 39597768. Its totient is φ = 10056512.

The previous prime is 21370133. The next prime is 21370157. The reversal of 21370156 is 65107312.

It is a self number, because there is not a number n which added to its sum of digits gives 21370156.

It is not an unprimeable number, because it can be changed into a prime (21370157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157066 + ... + 157201.

It is an arithmetic number, because the mean of its divisors is an integer number (3299814).

Almost surely, 2^21370156 is an apocalyptic number.

It is an amenable number.

21370156 is a deficient number, since it is larger than the sum of its proper divisors (18227612).

21370156 is a wasteful number, since it uses less digits than its factorization.

21370156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314288 (or 314286 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21370156 is about 4622.7866055011. The cubic root of 21370156 is about 277.5039893374.

Adding to 21370156 its reverse (65107312), we get a palindrome (86477468).

The spelling of 21370156 in words is "twenty-one million, three hundred seventy thousand, one hundred fifty-six".