121918139437 has 16 divisors (see below), whose sum is σ = 134479699200. Its totient is φ = 110050332160.

The previous prime is 121918139429. The next prime is 121918139459. The reversal of 121918139437 is 734931819121.

It is a cyclic number.

It is not a de Polignac number, because 121918139437 - 2³ = 121918139429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121918139537) 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, 1441237 + ... + 1523482.

It is an arithmetic number, because the mean of its divisors is an integer number (8404981200).

Almost surely, 2^121918139437 is an apocalyptic number.

121918139437 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

121918139437 is a deficient number, since it is larger than the sum of its proper divisors (12561559763).

121918139437 is a wasteful number, since it uses less digits than its factorization.

121918139437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2964836.

The product of its digits is 326592, while the sum is 49.

The spelling of 121918139437 in words is "one hundred twenty-one billion, nine hundred eighteen million, one hundred thirty-nine thousand, four hundred thirty-seven".