1398399138 has 12 divisors (see below), whose sum is σ = 3029864838. Its totient is φ = 466133040.

The previous prime is 1398399133. The next prime is 1398399139. The reversal of 1398399138 is 8319938931.

It can be written as a sum of positive squares in only one way, i.e., 788654889 + 609744249 = 28083^2 + 24693^2 .

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1398399133) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38844403 + ... + 38844438.

Almost surely, 2^1398399138 is an apocalyptic number.

1398399138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1398399138 is an abundant number, since it is smaller than the sum of its proper divisors (1631465700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1398399138 is a wasteful number, since it uses less digits than its factorization.

1398399138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77688849 (or 77688846 counting only the distinct ones).

The product of its digits is 1259712, while the sum is 54.

The square root of 1398399138 is about 37395.1753305156. The cubic root of 1398399138 is about 1118.2623826401.

The spelling of 1398399138 in words is "one billion, three hundred ninety-eight million, three hundred ninety-nine thousand, one hundred thirty-eight".