129850991 has 4 divisors (see below), whose sum is σ = 129892512. Its totient is φ = 129809472.

The previous prime is 129850961. The next prime is 129851003. The reversal of 129850991 is 199058921.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 129850991 - 2¹⁸ = 129588847 is a prime.

It is a super-2 number, since 2×129850991² = 33722559727364162, 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 (129850961) 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, 15650 + ... + 22463.

It is an arithmetic number, because the mean of its divisors is an integer number (32473128).

Almost surely, 2^129850991 is an apocalyptic number.

129850991 is a deficient number, since it is larger than the sum of its proper divisors (41521).

129850991 is an equidigital number, since it uses as much as digits as its factorization.

129850991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41520.

The product of its (nonzero) digits is 58320, while the sum is 44.

The square root of 129850991 is about 11395.2179005055. The cubic root of 129850991 is about 506.3860767972.

The spelling of 129850991 in words is "one hundred twenty-nine million, eight hundred fifty thousand, nine hundred ninety-one".