135944908621 has 2 divisors, whose sum is σ = 135944908622. Its totient is φ = 135944908620.

The previous prime is 135944908607. The next prime is 135944908643. The reversal of 135944908621 is 126809449531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84896476900 + 51048431721 = 291370^2 + 225939^2 .

It is a cyclic number.

It is not a de Polignac number, because 135944908621 - 2²¹ = 135942811469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135944908651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67972454310 + 67972454311.

It is an arithmetic number, because the mean of its divisors is an integer number (67972454311).

Almost surely, 2^135944908621 is an apocalyptic number.

It is an amenable number.

135944908621 is a deficient number, since it is larger than the sum of its proper divisors (1).

135944908621 is an equidigital number, since it uses as much as digits as its factorization.

135944908621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1866240, while the sum is 52.

The spelling of 135944908621 in words is "one hundred thirty-five billion, nine hundred forty-four million, nine hundred eight thousand, six hundred twenty-one".