1298128931 has 8 divisors (see below), whose sum is σ = 1420757184. Its totient is φ = 1176270120.

The previous prime is 1298128919. The next prime is 1298128933. The reversal of 1298128931 is 1398218921.

It is a happy number.

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 1298128931 - 2²² = 1293934627 is a prime.

It is a super-2 number, since 2×1298128931² = 3370277442998405522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1298128933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188825 + ... + 195578.

It is an arithmetic number, because the mean of its divisors is an integer number (177594648).

Almost surely, 2^1298128931 is an apocalyptic number.

1298128931 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1298128931 is a deficient number, since it is larger than the sum of its proper divisors (122628253).

1298128931 is a wasteful number, since it uses less digits than its factorization.

1298128931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384721.

The product of its digits is 62208, while the sum is 44.

The square root of 1298128931 is about 36029.5563530832. The cubic root of 1298128931 is about 1090.8690236044.

The spelling of 1298128931 in words is "one billion, two hundred ninety-eight million, one hundred twenty-eight thousand, nine hundred thirty-one".