21877765505 has 16 divisors (see below), whose sum is σ = 26542971840. Its totient is φ = 17309702592.

The previous prime is 21877765489. The next prime is 21877765519. The reversal of 21877765505 is 50556777812.

It is a cyclic number.

It is not a de Polignac number, because 21877765505 - 2⁴ = 21877765489 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 261422 + ... + 334808.

It is an arithmetic number, because the mean of its divisors is an integer number (1658935740).

Almost surely, 2^21877765505 is an apocalyptic number.

It is an amenable number.

21877765505 is a deficient number, since it is larger than the sum of its proper divisors (4665206335).

21877765505 is a wasteful number, since it uses less digits than its factorization.

21877765505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74048.

The product of its (nonzero) digits is 4116000, while the sum is 53.

The spelling of 21877765505 in words is "twenty-one billion, eight hundred seventy-seven million, seven hundred sixty-five thousand, five hundred five".