129721672 has 16 divisors (see below), whose sum is σ = 243349740. Its totient is φ = 64828416.

The previous prime is 129721651. The next prime is 129721693. The reversal of 129721672 is 276127921.

It is an interprime number because it is at equal distance from previous prime (129721651) and next prime (129721693).

It can be written as a sum of positive squares in 2 ways, for example, as 102535876 + 27185796 = 10126^2 + 5214^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26488 + ... + 31000.

Almost surely, 2^129721672 is an apocalyptic number.

It is an amenable number.

129721672 is a deficient number, since it is larger than the sum of its proper divisors (113628068).

129721672 is a wasteful number, since it uses less digits than its factorization.

129721672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8112 (or 8108 counting only the distinct ones).

The product of its digits is 21168, while the sum is 37.

The square root of 129721672 is about 11389.5422208270. The cubic root of 129721672 is about 506.2179171458.

It can be divided in two parts, 129 and 721672, that added together give a triangular number (721801 = T₁₂₀₁).

The spelling of 129721672 in words is "one hundred twenty-nine million, seven hundred twenty-one thousand, six hundred seventy-two".