101221099965 has 24 divisors (see below), whose sum is σ = 176048734680. Its totient is φ = 53800331904.

The previous prime is 101221099961. The next prime is 101221099999. The reversal of 101221099965 is 569990122101.

It can be written as a sum of positive squares in 4 ways, for example, as 14461986564 + 86759113401 = 120258^2 + 294549^2 .

It is not a de Polignac number, because 101221099965 - 2² = 101221099961 is a prime.

It is a super-2 number, since 2×101221099965² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 101221099965.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101221099961) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 3825310 + ... + 3851679.

It is an arithmetic number, because the mean of its divisors is an integer number (7335363945).

Almost surely, 2^101221099965 is an apocalyptic number.

101221099965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

101221099965 is a deficient number, since it is larger than the sum of its proper divisors (74827634715).

101221099965 is a wasteful number, since it uses less digits than its factorization.

101221099965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7677293 (or 7677290 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 45.

The spelling of 101221099965 in words is "one hundred one billion, two hundred twenty-one million, ninety-nine thousand, nine hundred sixty-five".