129893981 has 4 divisors (see below), whose sum is σ = 148450272. Its totient is φ = 111337692.

The previous prime is 129893941. The next prime is 129893983. The reversal of 129893981 is 189398921.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 189398921 = 17 ⋅11141113.

It is a cyclic number.

It is not a de Polignac number, because 129893981 - 2⁶ = 129893917 is a prime.

It is a super-2 number, since 2×129893981² = 33744892600056722, 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 (129893983) 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, 9278135 + ... + 9278148.

It is an arithmetic number, because the mean of its divisors is an integer number (37112568).

Almost surely, 2^129893981 is an apocalyptic number.

It is an amenable number.

129893981 is a deficient number, since it is larger than the sum of its proper divisors (18556291).

129893981 is an equidigital number, since it uses as much as digits as its factorization.

129893981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18556290.

The product of its digits is 279936, while the sum is 50.

The square root of 129893981 is about 11397.1040619975. The cubic root of 129893981 is about 506.4419540128.

The spelling of 129893981 in words is "one hundred twenty-nine million, eight hundred ninety-three thousand, nine hundred eighty-one".