129615421 has 8 divisors (see below), whose sum is σ = 140969304. Its totient is φ = 118459200.

The previous prime is 129615341. The next prime is 129615443. The reversal of 129615421 is 124516921.

It can be written as a sum of positive squares in 4 ways, for example, as 72914521 + 56700900 = 8539^2 + 7530^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 129615421 - 2⁹ = 129614909 is a prime.

It is a super-2 number, since 2×129615421² = 33600314722014482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129615121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48046 + ... + 50671.

It is an arithmetic number, because the mean of its divisors is an integer number (17621163).

Almost surely, 2^129615421 is an apocalyptic number.

It is an amenable number.

129615421 is a deficient number, since it is larger than the sum of its proper divisors (11353883).

129615421 is a wasteful number, since it uses less digits than its factorization.

129615421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98831.

The product of its digits is 4320, while the sum is 31.

The square root of 129615421 is about 11384.8768548456. The cubic root of 129615421 is about 506.0796702602.

The spelling of 129615421 in words is "one hundred twenty-nine million, six hundred fifteen thousand, four hundred twenty-one".