77734621581 has 16 divisors (see below), whose sum is σ = 105875589120. Its totient is φ = 50716246320.

The previous prime is 77734621579. The next prime is 77734621607. The reversal of 77734621581 is 18512643777.

It is not a de Polignac number, because 77734621581 - 2¹ = 77734621579 is a prime.

It is a super-2 number, since 2×77734621581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77734121581) 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, 945235 + ... + 1024176.

It is an arithmetic number, because the mean of its divisors is an integer number (6617224320).

Almost surely, 2^77734621581 is an apocalyptic number.

It is an amenable number.

77734621581 is a deficient number, since it is larger than the sum of its proper divisors (28140967539).

77734621581 is a wasteful number, since it uses less digits than its factorization.

77734621581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1969696.

The product of its digits is 1975680, while the sum is 51.

The spelling of 77734621581 in words is "seventy-seven billion, seven hundred thirty-four million, six hundred twenty-one thousand, five hundred eighty-one".