21970537 has 8 divisors (see below), whose sum is σ = 22740480. Its totient is φ = 21204480.

The previous prime is 21970513. The next prime is 21970577. The reversal of 21970537 is 73507912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21970537 - 2¹¹ = 21968489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21970577) 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, 14889 + ... + 16297.

It is an arithmetic number, because the mean of its divisors is an integer number (2842560).

Almost surely, 2^21970537 is an apocalyptic number.

It is an amenable number.

21970537 is a deficient number, since it is larger than the sum of its proper divisors (769943).

21970537 is a wasteful number, since it uses less digits than its factorization.

21970537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943.

The product of its (nonzero) digits is 13230, while the sum is 34.

The square root of 21970537 is about 4687.2739412157. The cubic root of 21970537 is about 280.0787916016.

It can be divided in two parts, 219 and 70537, that added together give a square (70756 = 266²).

The spelling of 21970537 in words is "twenty-one million, nine hundred seventy thousand, five hundred thirty-seven".