139287998 has 4 divisors (see below), whose sum is σ = 208932000. Its totient is φ = 69643998.

The previous prime is 139287997. The next prime is 139288001. The reversal of 139287998 is 899782931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 899782931 = 23 ⋅39120997.

It is a super-2 number, since 2×139287998² = 38802292773696008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139287997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34821998 + ... + 34822001.

It is an arithmetic number, because the mean of its divisors is an integer number (52233000).

Almost surely, 2^139287998 is an apocalyptic number.

139287998 is a deficient number, since it is larger than the sum of its proper divisors (69644002).

139287998 is an equidigital number, since it uses as much as digits as its factorization.

139287998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69644001.

The product of its digits is 1959552, while the sum is 56.

The square root of 139287998 is about 11802.0336383184. The cubic root of 139287998 is about 518.3676598568.

The spelling of 139287998 in words is "one hundred thirty-nine million, two hundred eighty-seven thousand, nine hundred ninety-eight".