139724999 has 4 divisors (see below), whose sum is σ = 140024664. Its totient is φ = 139425336.

The previous prime is 139724971. The next prime is 139725043. The reversal of 139724999 is 999427931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 139724999 - 2⁸ = 139724743 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 139724999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139724909) 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, 149132 + ... + 150065.

It is an arithmetic number, because the mean of its divisors is an integer number (35006166).

Almost surely, 2^139724999 is an apocalyptic number.

139724999 is a deficient number, since it is larger than the sum of its proper divisors (299665).

139724999 is an equidigital number, since it uses as much as digits as its factorization.

139724999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299664.

The product of its digits is 1102248, while the sum is 53.

The square root of 139724999 is about 11820.5329406081. The cubic root of 139724999 is about 518.9092013620.

The spelling of 139724999 in words is "one hundred thirty-nine million, seven hundred twenty-four thousand, nine hundred ninety-nine".