139696421 has 4 divisors (see below), whose sum is σ = 139735200. Its totient is φ = 139657644.

The previous prime is 139696391. The next prime is 139696477. The reversal of 139696421 is 124696931.

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: 124696931 = 619 ⋅201449.

It is a cyclic number.

It is not a de Polignac number, because 139696421 - 2⁶ = 139696357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139696321) 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, 13361 + ... + 21398.

It is an arithmetic number, because the mean of its divisors is an integer number (34933800).

Almost surely, 2^139696421 is an apocalyptic number.

It is an amenable number.

139696421 is a deficient number, since it is larger than the sum of its proper divisors (38779).

139696421 is an equidigital number, since it uses as much as digits as its factorization.

139696421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38778.

The product of its digits is 69984, while the sum is 41.

The square root of 139696421 is about 11819.3240500462. The cubic root of 139696421 is about 518.8738213933.

The spelling of 139696421 in words is "one hundred thirty-nine million, six hundred ninety-six thousand, four hundred twenty-one".