19907979 has 16 divisors (see below), whose sum is σ = 32669952. Its totient is φ = 10500768.

The previous prime is 19907963. The next prime is 19907981. The reversal of 19907979 is 97970991.

It is not a de Polignac number, because 19907979 - 2⁴ = 19907963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19907929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36189 + ... + 36734.

It is an arithmetic number, because the mean of its divisors is an integer number (2041872).

Almost surely, 2^19907979 is an apocalyptic number.

19907979 is a deficient number, since it is larger than the sum of its proper divisors (12761973).

19907979 is a wasteful number, since it uses less digits than its factorization.

19907979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72946.

The product of its (nonzero) digits is 321489, while the sum is 51.

The square root of 19907979 is about 4461.8358329280. The cubic root of 19907979 is about 271.0248158355.

The spelling of 19907979 in words is "nineteen million, nine hundred seven thousand, nine hundred seventy-nine".