121609872 has 30 divisors (see below), whose sum is σ = 340339142. Its totient is φ = 40536576.

The previous prime is 121609871. The next prime is 121609903. The reversal of 121609872 is 278906121.

It can be written as a sum of positive squares in only one way, i.e., 119771136 + 1838736 = 10944^2 + 1356^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (121609871) 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, 422113 + ... + 422400.

Almost surely, 2^121609872 is an apocalyptic number.

121609872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

121609872 is an abundant number, since it is smaller than the sum of its proper divisors (218729270).

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

121609872 is a wasteful number, since it uses less digits than its factorization.

121609872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844527 (or 844518 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 121609872 is about 11027.6866114340. The cubic root of 121609872 is about 495.4383383833.

The spelling of 121609872 in words is "one hundred twenty-one million, six hundred nine thousand, eight hundred seventy-two".