139879421 has 4 divisors (see below), whose sum is σ = 152595744. Its totient is φ = 127163100.

The previous prime is 139879393. The next prime is 139879433. The reversal of 139879421 is 124978931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 139879421 - 2¹⁴ = 139863037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139879021) 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, 6358145 + ... + 6358166.

It is an arithmetic number, because the mean of its divisors is an integer number (38148936).

Almost surely, 2^139879421 is an apocalyptic number.

139879421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

139879421 is a deficient number, since it is larger than the sum of its proper divisors (12716323).

139879421 is a wasteful number, since it uses less digits than its factorization.

139879421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12716322.

The product of its digits is 108864, while the sum is 44.

The square root of 139879421 is about 11827.0630758443. The cubic root of 139879421 is about 519.1002945701.

The spelling of 139879421 in words is "one hundred thirty-nine million, eight hundred seventy-nine thousand, four hundred twenty-one".