1945397721629 has 2 divisors, whose sum is σ = 1945397721630. Its totient is φ = 1945397721628.

The previous prime is 1945397721599. The next prime is 1945397721671. The reversal of 1945397721629 is 9261277935491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1022116956004 + 923280765625 = 1010998^2 + 960875^2 .

It is a cyclic number.

It is not a de Polignac number, because 1945397721629 - 2²⁴ = 1945380944413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1945397721529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 972698860814 + 972698860815.

It is an arithmetic number, because the mean of its divisors is an integer number (972698860815).

Almost surely, 2^{1945397721629} is an apocalyptic number.

It is an amenable number.

1945397721629 is a deficient number, since it is larger than the sum of its proper divisors (1).

1945397721629 is an equidigital number, since it uses as much as digits as its factorization.

1945397721629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51438240, while the sum is 65.

The spelling of 1945397721629 in words is "one trillion, nine hundred forty-five billion, three hundred ninety-seven million, seven hundred twenty-one thousand, six hundred twenty-nine".