78121884 has 48 divisors (see below), whose sum is σ = 188496000. Its totient is φ = 25166400.

The previous prime is 78121873. The next prime is 78121903. The reversal of 78121884 is 48812187.

78121884 = T₄₃₂ + T₄₃₃ + ... + T₈₁₈.

It is a happy number.

It is a super-2 number, since 2×78121884² = 12206057519418912, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51367 + ... + 52865.

It is an arithmetic number, because the mean of its divisors is an integer number (3927000).

Almost surely, 2^78121884 is an apocalyptic number.

It is an amenable number.

78121884 is an abundant number, since it is smaller than the sum of its proper divisors (110374116).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78121884 is a wasteful number, since it uses less digits than its factorization.

78121884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1650 (or 1648 counting only the distinct ones).

The product of its digits is 28672, while the sum is 39.

The square root of 78121884 is about 8838.6584954958. The cubic root of 78121884 is about 427.4883030896.

The spelling of 78121884 in words is "seventy-eight million, one hundred twenty-one thousand, eight hundred eighty-four".