129725401 has 4 divisors (see below), whose sum is σ = 139704292. Its totient is φ = 119746512.

The previous prime is 129725399. The next prime is 129725411. The reversal of 129725401 is 104527921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 104527921 = 8681 ⋅12041.

It can be written as a sum of positive squares in 2 ways, for example, as 50069776 + 79655625 = 7076^2 + 8925^2 .

It is a cyclic number.

It is not a de Polignac number, because 129725401 - 2¹ = 129725399 is a prime.

It is a super-2 number, since 2×129725401² = 33657359329221602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129725411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4989426 + ... + 4989451.

It is an arithmetic number, because the mean of its divisors is an integer number (34926073).

Almost surely, 2^129725401 is an apocalyptic number.

It is an amenable number.

129725401 is a deficient number, since it is larger than the sum of its proper divisors (9978891).

129725401 is an equidigital number, since it uses as much as digits as its factorization.

129725401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9978890.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 129725401 is about 11389.7059224547. The cubic root of 129725401 is about 506.2227677065. Note that the first 3 decimals are identical.

The spelling of 129725401 in words is "one hundred twenty-nine million, seven hundred twenty-five thousand, four hundred one".