20981079 has 32 divisors (see below), whose sum is σ = 36679680. Its totient is φ = 11599200.

The previous prime is 20981069. The next prime is 20981089. The reversal of 20981079 is 97018902.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20981069) and next prime (20981089).

It is not a de Polignac number, because 20981079 - 2⁴ = 20981063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20981029) 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, 4069 + ... + 7649.

It is an arithmetic number, because the mean of its divisors is an integer number (1146240).

Almost surely, 2^20981079 is an apocalyptic number.

20981079 is a deficient number, since it is larger than the sum of its proper divisors (15698601).

20981079 is a wasteful number, since it uses less digits than its factorization.

20981079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3628 (or 3622 counting only the distinct ones).

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

The square root of 20981079 is about 4580.5107793782. The cubic root of 20981079 is about 275.8095330507.

The spelling of 20981079 in words is "twenty million, nine hundred eighty-one thousand, seventy-nine".