129421641 has 4 divisors (see below), whose sum is σ = 172562192. Its totient is φ = 86281092.

The previous prime is 129421639. The next prime is 129421723. The reversal of 129421641 is 146124921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 129421641 - 2¹ = 129421639 is a prime.

It is a super-2 number, since 2×129421641² = 33499922318265762, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129421599 and 129421608.

It is not an unprimeable number, because it can be changed into a prime (129421541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21570271 + ... + 21570276.

It is an arithmetic number, because the mean of its divisors is an integer number (43140548).

Almost surely, 2^129421641 is an apocalyptic number.

It is an amenable number.

129421641 is a deficient number, since it is larger than the sum of its proper divisors (43140551).

129421641 is an equidigital number, since it uses as much as digits as its factorization.

129421641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43140550.

The product of its digits is 3456, while the sum is 30.

The square root of 129421641 is about 11376.3632589681. The cubic root of 129421641 is about 505.8273416658.

The spelling of 129421641 in words is "one hundred twenty-nine million, four hundred twenty-one thousand, six hundred forty-one".