121587639 has 4 divisors (see below), whose sum is σ = 162116856. Its totient is φ = 81058424.

The previous prime is 121587619. The next prime is 121587659. The reversal of 121587639 is 936785121.

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

It is an interprime number because it is at equal distance from previous prime (121587619) and next prime (121587659).

It is a cyclic number.

It is not a de Polignac number, because 121587639 - 2⁹ = 121587127 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121587639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121587619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20264604 + ... + 20264609.

It is an arithmetic number, because the mean of its divisors is an integer number (40529214).

Almost surely, 2^121587639 is an apocalyptic number.

121587639 is a deficient number, since it is larger than the sum of its proper divisors (40529217).

121587639 is an equidigital number, since it uses as much as digits as its factorization.

121587639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40529216.

The product of its digits is 90720, while the sum is 42.

The square root of 121587639 is about 11026.6785116825. The cubic root of 121587639 is about 495.4081441462.

The spelling of 121587639 in words is "one hundred twenty-one million, five hundred eighty-seven thousand, six hundred thirty-nine".