1272121878 has 16 divisors (see below), whose sum is σ = 2544894576. Its totient is φ = 423932160.

The previous prime is 1272121843. The next prime is 1272121891. The reversal of 1272121878 is 8781212721.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 450 + ... + 50442.

It is an arithmetic number, because the mean of its divisors is an integer number (159055911).

Almost surely, 2^1272121878 is an apocalyptic number.

1272121878 is an abundant number, since it is smaller than the sum of its proper divisors (1272772698).

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

1272121878 is a wasteful number, since it uses less digits than its factorization.

1272121878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54239.

The product of its digits is 25088, while the sum is 39.

The square root of 1272121878 is about 35666.8176040420. The cubic root of 1272121878 is about 1083.5349074589.

The spelling of 1272121878 in words is "one billion, two hundred seventy-two million, one hundred twenty-one thousand, eight hundred seventy-eight".