1398699631 has 4 divisors (see below), whose sum is σ = 1598513872. Its totient is φ = 1198885392.

The previous prime is 1398699623. The next prime is 1398699647. The reversal of 1398699631 is 1369968931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1369968931 = 6271 ⋅218461.

It is a cyclic number.

It is not a de Polignac number, because 1398699631 - 2³ = 1398699623 is a prime.

It is a super-3 number, since 3×1398699631³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398699671) 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, 99907110 + ... + 99907123.

It is an arithmetic number, because the mean of its divisors is an integer number (399628468).

Almost surely, 2^1398699631 is an apocalyptic number.

1398699631 is a deficient number, since it is larger than the sum of its proper divisors (199814241).

1398699631 is an equidigital number, since it uses as much as digits as its factorization.

1398699631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199814240.

The product of its digits is 1889568, while the sum is 55.

The square root of 1398699631 is about 37399.1929190992. The cubic root of 1398699631 is about 1118.3424756414.

The spelling of 1398699631 in words is "one billion, three hundred ninety-eight million, six hundred ninety-nine thousand, six hundred thirty-one".