21177156715 has 16 divisors (see below), whose sum is σ = 29855349216. Its totient is φ = 14216832000.

The previous prime is 21177156713. The next prime is 21177156733. The reversal of 21177156715 is 51765177112.

It is not a de Polignac number, because 21177156715 - 2¹ = 21177156713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21177156713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14808486 + ... + 14809915.

It is an arithmetic number, because the mean of its divisors is an integer number (1865959326).

Almost surely, 2^21177156715 is an apocalyptic number.

21177156715 is a deficient number, since it is larger than the sum of its proper divisors (8678192501).

21177156715 is a wasteful number, since it uses less digits than its factorization.

21177156715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29618430.

The product of its digits is 102900, while the sum is 43.

The spelling of 21177156715 in words is "twenty-one billion, one hundred seventy-seven million, one hundred fifty-six thousand, seven hundred fifteen".