19977717947 has 12 divisors (see below), whose sum is σ = 22054900560. Its totient is φ = 18082228560.

The previous prime is 19977717931. The next prime is 19977717961. The reversal of 19977717947 is 74971777991.

It is not a de Polignac number, because 19977717947 - 2⁴ = 19977717931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19977717967) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 332783 + ... + 388200.

It is an arithmetic number, because the mean of its divisors is an integer number (1837908380).

Almost surely, 2^19977717947 is an apocalyptic number.

19977717947 is a deficient number, since it is larger than the sum of its proper divisors (2077182613).

19977717947 is a wasteful number, since it uses less digits than its factorization.

19977717947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721234 (or 721223 counting only the distinct ones).

The product of its digits is 49009212, while the sum is 68.

The spelling of 19977717947 in words is "nineteen billion, nine hundred seventy-seven million, seven hundred seventeen thousand, nine hundred forty-seven".