83121561426728 has 64 divisors (see below), whose sum is σ = 170689280054400. Its totient is φ = 37634115665920.

The previous prime is 83121561426707. The next prime is 83121561426833. The reversal of 83121561426728 is 82762416512138.

It is a super-2 number, since 2×83121561426728² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 833508053 + ... + 833607771.

It is an arithmetic number, because the mean of its divisors is an integer number (2667020000850).

Almost surely, 2^{83121561426728} is an apocalyptic number.

83121561426728 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

83121561426728 is an abundant number, since it is smaller than the sum of its proper divisors (87567718627672).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

83121561426728 is a wasteful number, since it uses less digits than its factorization.

83121561426728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136850 (or 136846 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 56.

The spelling of 83121561426728 in words is "eighty-three trillion, one hundred twenty-one billion, five hundred sixty-one million, four hundred twenty-six thousand, seven hundred twenty-eight".