139631921 has 8 divisors (see below), whose sum is σ = 164043264. Its totient is φ = 117173520.

The previous prime is 139631911. The next prime is 139631959. The reversal of 139631921 is 129136931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 139631921 - 2⁶ = 139631857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (139631911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 488081 + ... + 488366.

It is an arithmetic number, because the mean of its divisors is an integer number (20505408).

Almost surely, 2^139631921 is an apocalyptic number.

139631921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

139631921 is a deficient number, since it is larger than the sum of its proper divisors (24411343).

139631921 is a wasteful number, since it uses less digits than its factorization.

139631921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976471.

The product of its digits is 8748, while the sum is 35.

The square root of 139631921 is about 11816.5951525810. The cubic root of 139631921 is about 518.7939517413.

The spelling of 139631921 in words is "one hundred thirty-nine million, six hundred thirty-one thousand, nine hundred twenty-one".