21777139955 has 8 divisors (see below), whose sum is σ = 26769947904. Its totient is φ = 16996792000.

The previous prime is 21777139931. The next prime is 21777139973. The reversal of 21777139955 is 55993177712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21777139955 - 2²⁴ = 21760362739 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21777139955.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53114771 + ... + 53115180.

It is an arithmetic number, because the mean of its divisors is an integer number (3346243488).

Almost surely, 2^21777139955 is an apocalyptic number.

21777139955 is a deficient number, since it is larger than the sum of its proper divisors (4992807949).

21777139955 is a wasteful number, since it uses less digits than its factorization.

21777139955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106229997.

The product of its digits is 4167450, while the sum is 56.

The spelling of 21777139955 in words is "twenty-one billion, seven hundred seventy-seven million, one hundred thirty-nine thousand, nine hundred fifty-five".