20906739 has 24 divisors (see below), whose sum is σ = 35449440. Its totient is φ = 11622528.

The previous prime is 20906737. The next prime is 20906749. The reversal of 20906739 is 93760902.

It is not a de Polignac number, because 20906739 - 2¹ = 20906737 is a prime.

It is a super-2 number, since 2×20906739² = 874183471228242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20906737) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2154 + ... + 6815.

It is an arithmetic number, because the mean of its divisors is an integer number (1477060).

Almost surely, 2^20906739 is an apocalyptic number.

20906739 is a deficient number, since it is larger than the sum of its proper divisors (14542701).

20906739 is a wasteful number, since it uses less digits than its factorization.

20906739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9019 (or 9016 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 20906739 is about 4572.3887629991. The cubic root of 20906739 is about 275.4833988128.

The spelling of 20906739 in words is "twenty million, nine hundred six thousand, seven hundred thirty-nine".