21977155537529 has 16 divisors (see below), whose sum is σ = 22089529469952. Its totient is φ = 21865069594368.

The previous prime is 21977155537507. The next prime is 21977155537553. The reversal of 21977155537529 is 92573555177912.

It is a cyclic number.

It is not a de Polignac number, because 21977155537529 - 2⁸ = 21977155537273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21977155557529) 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, 840317117 + ... + 840343269.

It is an arithmetic number, because the mean of its divisors is an integer number (1380595591872).

Almost surely, 2^{21977155537529} is an apocalyptic number.

It is an amenable number.

21977155537529 is a deficient number, since it is larger than the sum of its proper divisors (112373932423).

21977155537529 is a wasteful number, since it uses less digits than its factorization.

21977155537529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31496.

The product of its digits is 208372500, while the sum is 68.

The spelling of 21977155537529 in words is "twenty-one trillion, nine hundred seventy-seven billion, one hundred fifty-five million, five hundred thirty-seven thousand, five hundred twenty-nine".