20980971 has 32 divisors (see below), whose sum is σ = 34755840. Its totient is φ = 12398400.

The previous prime is 20980957. The next prime is 20980987. The reversal of 20980971 is 17908902.

It is a happy number.

It is not a de Polignac number, because 20980971 - 2²¹ = 18883819 is a prime.

It is a super-2 number, since 2×20980971² = 880402288205682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20980901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11316 + ... + 13038.

It is an arithmetic number, because the mean of its divisors is an integer number (1086120).

Almost surely, 2^20980971 is an apocalyptic number.

20980971 is a deficient number, since it is larger than the sum of its proper divisors (13774869).

20980971 is a wasteful number, since it uses less digits than its factorization.

20980971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1784 (or 1778 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 20980971 is about 4580.4989902848. The cubic root of 20980971 is about 275.8090598071.

The spelling of 20980971 in words is "twenty million, nine hundred eighty thousand, nine hundred seventy-one".