20706537 has 4 divisors (see below), whose sum is σ = 27608720. Its totient is φ = 13804356.

The previous prime is 20706503. The next prime is 20706557. The reversal of 20706537 is 73560702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20706537 - 2¹⁰ = 20705513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20706557) 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, 3451087 + ... + 3451092.

It is an arithmetic number, because the mean of its divisors is an integer number (6902180).

Almost surely, 2^20706537 is an apocalyptic number.

It is an amenable number.

20706537 is a deficient number, since it is larger than the sum of its proper divisors (6902183).

20706537 is an equidigital number, since it uses as much as digits as its factorization.

20706537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6902182.

The product of its (nonzero) digits is 8820, while the sum is 30.

The square root of 20706537 is about 4550.4436047489. The cubic root of 20706537 is about 274.6012380352.

The spelling of 20706537 in words is "twenty million, seven hundred six thousand, five hundred thirty-seven".