1545361621 has 2 divisors, whose sum is σ = 1545361622. Its totient is φ = 1545361620.

The previous prime is 1545361619. The next prime is 1545361663. The reversal of 1545361621 is 1261635451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1126340721 + 419020900 = 33561^2 + 20470^2 .

It is a cyclic number.

It is not a de Polignac number, because 1545361621 - 2¹ = 1545361619 is a prime.

Together with 1545361619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1545361021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 772680810 + 772680811.

It is an arithmetic number, because the mean of its divisors is an integer number (772680811).

Almost surely, 2^1545361621 is an apocalyptic number.

It is an amenable number.

1545361621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1545361621 is an equidigital number, since it uses as much as digits as its factorization.

1545361621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21600, while the sum is 34.

The square root of 1545361621 is about 39311.0877615972. The cubic root of 1545361621 is about 1156.1389715410.

The spelling of 1545361621 in words is "one billion, five hundred forty-five million, three hundred sixty-one thousand, six hundred twenty-one".