20477139977 has 16 divisors (see below), whose sum is σ = 23457088512. Its totient is φ = 17510910480.

The previous prime is 20477139973. The next prime is 20477139979. The reversal of 20477139977 is 77993177402.

It is not a de Polignac number, because 20477139977 - 2² = 20477139973 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20477139973) 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, 7335452 + ... + 7338242.

It is an arithmetic number, because the mean of its divisors is an integer number (1466068032).

Almost surely, 2^20477139977 is an apocalyptic number.

It is an amenable number.

20477139977 is a deficient number, since it is larger than the sum of its proper divisors (2979948535).

20477139977 is a wasteful number, since it uses less digits than its factorization.

20477139977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4868.

The product of its (nonzero) digits is 4667544, while the sum is 56.

The spelling of 20477139977 in words is "twenty billion, four hundred seventy-seven million, one hundred thirty-nine thousand, nine hundred seventy-seven".