121539026991 has 8 divisors (see below), whose sum is σ = 162054312064. Its totient is φ = 81024879960.

The previous prime is 121539026969. The next prime is 121539027007. The reversal of 121539026991 is 199620935121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121539026991 - 2¹⁵ = 121538994223 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121539026991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121539022991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7500 + ... + 493086.

It is an arithmetic number, because the mean of its divisors is an integer number (20256789008).

Almost surely, 2^121539026991 is an apocalyptic number.

121539026991 is a deficient number, since it is larger than the sum of its proper divisors (40515285073).

121539026991 is an equidigital number, since it uses as much as digits as its factorization.

121539026991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569021.

The product of its (nonzero) digits is 262440, while the sum is 48.

The spelling of 121539026991 in words is "one hundred twenty-one billion, five hundred thirty-nine million, twenty-six thousand, nine hundred ninety-one".