121985621659 has 16 divisors (see below), whose sum is σ = 135636871680. Its totient is φ = 108762881760.

The previous prime is 121985621657. The next prime is 121985621677. The reversal of 121985621659 is 956126589121.

It is a cyclic number.

It is not a de Polignac number, because 121985621659 - 2¹ = 121985621657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121985621657) 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, 1575352 + ... + 1650970.

It is an arithmetic number, because the mean of its divisors is an integer number (8477304480).

Almost surely, 2^121985621659 is an apocalyptic number.

121985621659 is a deficient number, since it is larger than the sum of its proper divisors (13651250021).

121985621659 is a wasteful number, since it uses less digits than its factorization.

121985621659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78450.

The product of its digits is 2332800, while the sum is 55.

It can be divided in two parts, 12198562 and 1659, that added together give a palindrome (12200221).

The spelling of 121985621659 in words is "one hundred twenty-one billion, nine hundred eighty-five million, six hundred twenty-one thousand, six hundred fifty-nine".