101989977581 has 4 divisors (see below), whose sum is σ = 104159977152. Its totient is φ = 99819978012.

The previous prime is 101989977541. The next prime is 101989977623. The reversal of 101989977581 is 185779989101.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 101989977581 - 2⁶ = 101989977517 is a prime.

It is a super-2 number, since 2×101989977581² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101989977541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1084999715 + ... + 1084999808.

It is an arithmetic number, because the mean of its divisors is an integer number (26039994288).

Almost surely, 2^101989977581 is an apocalyptic number.

It is an amenable number.

101989977581 is a deficient number, since it is larger than the sum of its proper divisors (2169999571).

101989977581 is an equidigital number, since it uses as much as digits as its factorization.

101989977581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2169999570.

The product of its (nonzero) digits is 11430720, while the sum is 65.

The spelling of 101989977581 in words is "one hundred one billion, nine hundred eighty-nine million, nine hundred seventy-seven thousand, five hundred eighty-one".