139321551 has 4 divisors (see below), whose sum is σ = 185762072. Its totient is φ = 92881032.

The previous prime is 139321543. The next prime is 139321561. The reversal of 139321551 is 155123931.

139321551 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 an emirpimes, since its reverse is a distinct semiprime: 155123931 = 3 ⋅51707977.

It is not a de Polignac number, because 139321551 - 2³ = 139321543 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 (139321531) 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, 23220256 + ... + 23220261.

It is an arithmetic number, because the mean of its divisors is an integer number (46440518).

Almost surely, 2^139321551 is an apocalyptic number.

139321551 is a deficient number, since it is larger than the sum of its proper divisors (46440521).

139321551 is an equidigital number, since it uses as much as digits as its factorization.

139321551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46440520.

The product of its digits is 4050, while the sum is 30.

The square root of 139321551 is about 11803.4550450281. The cubic root of 139321551 is about 518.4092796038.

The spelling of 139321551 in words is "one hundred thirty-nine million, three hundred twenty-one thousand, five hundred fifty-one".