139071421 has 4 divisors (see below), whose sum is σ = 139904352. Its totient is φ = 138238492.

The previous prime is 139071391. The next prime is 139071461. The reversal of 139071421 is 124170931.

139071421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 124170931 = 89 ⋅1395179.

It is a cyclic number.

It is not a de Polignac number, because 139071421 - 2⁷ = 139071293 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 139071421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139071461) 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, 416215 + ... + 416548.

It is an arithmetic number, because the mean of its divisors is an integer number (34976088).

Almost surely, 2^139071421 is an apocalyptic number.

It is an amenable number.

139071421 is a deficient number, since it is larger than the sum of its proper divisors (832931).

139071421 is an equidigital number, since it uses as much as digits as its factorization.

139071421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832930.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 139071421 is about 11792.8546586482. The cubic root of 139071421 is about 518.0988528961.

The spelling of 139071421 in words is "one hundred thirty-nine million, seventy-one thousand, four hundred twenty-one".