1209979872 has 36 divisors (see below), whose sum is σ = 3440881080. Its totient is φ = 403326528.

The previous prime is 1209979871. The next prime is 1209979873. The reversal of 1209979872 is 2789799021.

It is an interprime number because it is at equal distance from previous prime (1209979871) and next prime (1209979873).

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209979871) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2100372 + ... + 2100947.

It is an arithmetic number, because the mean of its divisors is an integer number (95580030).

Almost surely, 2^1209979872 is an apocalyptic number.

1209979872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1209979872 is an abundant number, since it is smaller than the sum of its proper divisors (2230901208).

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

1209979872 is a wasteful number, since it uses less digits than its factorization.

1209979872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4201335 (or 4201324 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 54.

The square root of 1209979872 is about 34784.7649409910. The cubic root of 1209979872 is about 1065.5963280722.

The spelling of 1209979872 in words is "one billion, two hundred nine million, nine hundred seventy-nine thousand, eight hundred seventy-two".