101221099979 has 4 divisors (see below), whose sum is σ = 101224341720. Its totient is φ = 101217858240.

The previous prime is 101221099961. The next prime is 101221099999. The reversal of 101221099979 is 979990122101.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 101221099979 - 2⁸ = 101221099723 is a prime.

It is a super-2 number, since 2×101221099979² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101221099919) 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, 1573574 + ... + 1636635.

It is an arithmetic number, because the mean of its divisors is an integer number (25306085430).

Almost surely, 2^101221099979 is an apocalyptic number.

101221099979 is a deficient number, since it is larger than the sum of its proper divisors (3241741).

101221099979 is an equidigital number, since it uses as much as digits as its factorization.

101221099979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3241740.

The product of its (nonzero) digits is 183708, while the sum is 50.

The spelling of 101221099979 in words is "one hundred one billion, two hundred twenty-one million, ninety-nine thousand, nine hundred seventy-nine".