139923135445921 has 27 divisors (see below), whose sum is σ = 144405639947289. Its totient is φ = 135578624842752.

The previous prime is 139923135445859. The next prime is 139923135445967. The reversal of 139923135445921 is 129544531329931.

The square root of 139923135445921 is 11828911.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 17865626900625 + 122057508545296 = 4226775^2 + 11047964^2 .

It is not a de Polignac number, because 139923135445921 - 2¹⁵ = 139923135413153 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 139923135445921.

It is not an unprimeable number, because it can be changed into a prime (139923115445921) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 52035378145 + ... + 52035380833.

Almost surely, 2^{139923135445921} is an apocalyptic number.

139923135445921 is the 11828911-st square number.

139923135445921 is the 5914456-th centered octagonal number.

It is an amenable number.

139923135445921 is a deficient number, since it is larger than the sum of its proper divisors (4482504501368).

139923135445921 is an frugal number, since it uses more digits than its factorization.

139923135445921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5650 (or 2825 counting only the distinct ones).

The product of its digits is 31492800, while the sum is 61.

The spelling of 139923135445921 in words is "one hundred thirty-nine trillion, nine hundred twenty-three billion, one hundred thirty-five million, four hundred forty-five thousand, nine hundred twenty-one".