139403421 has 6 divisors (see below), whose sum is σ = 201360510. Its totient is φ = 92935608.

The previous prime is 139403419. The next prime is 139403423. The reversal of 139403421 is 124304931.

It is an interprime number because it is at equal distance from previous prime (139403419) and next prime (139403423).

It can be written as a sum of positive squares in only one way, i.e., 107931321 + 31472100 = 10389^2 + 5610^2 .

It is not a de Polignac number, because 139403421 - 2¹ = 139403419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139403423) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7744626 + ... + 7744643.

It is an arithmetic number, because the mean of its divisors is an integer number (33560085).

Almost surely, 2^139403421 is an apocalyptic number.

It is an amenable number.

139403421 is a deficient number, since it is larger than the sum of its proper divisors (61957089).

139403421 is a wasteful number, since it uses less digits than its factorization.

139403421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15489275 (or 15489272 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 139403421 is about 11806.9225880413. The cubic root of 139403421 is about 518.5108045932.

The spelling of 139403421 in words is "one hundred thirty-nine million, four hundred three thousand, four hundred twenty-one".