135420361621 has 2 divisors, whose sum is σ = 135420361622. Its totient is φ = 135420361620.

The previous prime is 135420361597. The next prime is 135420361667. The reversal of 135420361621 is 126163024531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126514664721 + 8905696900 = 355689^2 + 94370^2 .

It is an emirp because it is prime and its reverse (126163024531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 135420361621 - 2¹³ = 135420353429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135426361621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67710180810 + 67710180811.

It is an arithmetic number, because the mean of its divisors is an integer number (67710180811).

Almost surely, 2^135420361621 is an apocalyptic number.

It is an amenable number.

135420361621 is a deficient number, since it is larger than the sum of its proper divisors (1).

135420361621 is an equidigital number, since it uses as much as digits as its factorization.

135420361621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 34.

The spelling of 135420361621 in words is "one hundred thirty-five billion, four hundred twenty million, three hundred sixty-one thousand, six hundred twenty-one".