398878068731 has 2 divisors, whose sum is σ = 398878068732. Its totient is φ = 398878068730.

The previous prime is 398878068689. The next prime is 398878068739. The reversal of 398878068731 is 137860878893.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398878068731 is a prime.

It is a super-2 number, since 2×398878068731² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (398878068739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199439034365 + 199439034366.

It is an arithmetic number, because the mean of its divisors is an integer number (199439034366).

Almost surely, 2^398878068731 is an apocalyptic number.

398878068731 is a deficient number, since it is larger than the sum of its proper divisors (1).

398878068731 is an equidigital number, since it uses as much as digits as its factorization.

398878068731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97542144, while the sum is 68.

The spelling of 398878068731 in words is "three hundred ninety-eight billion, eight hundred seventy-eight million, sixty-eight thousand, seven hundred thirty-one".