616561493 has 2 divisors, whose sum is σ = 616561494. Its totient is φ = 616561492.

The previous prime is 616561481. The next prime is 616561523. The reversal of 616561493 is 394165616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609201124 + 7360369 = 24682^2 + 2713^2 .

It is a cyclic number.

It is not a de Polignac number, because 616561493 - 2²⁴ = 599784277 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 616561493.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (616551493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 308280746 + 308280747.

It is an arithmetic number, because the mean of its divisors is an integer number (308280747).

Almost surely, 2^616561493 is an apocalyptic number.

It is an amenable number.

616561493 is a deficient number, since it is larger than the sum of its proper divisors (1).

616561493 is an equidigital number, since it uses as much as digits as its factorization.

616561493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 41.

The square root of 616561493 is about 24830.6563143224. The cubic root of 616561493 is about 851.1226195547.

The spelling of 616561493 in words is "six hundred sixteen million, five hundred sixty-one thousand, four hundred ninety-three".