1649566993 has 2 divisors, whose sum is σ = 1649566994. Its totient is φ = 1649566992.

The previous prime is 1649566991. The next prime is 1649566999. The reversal of 1649566993 is 3996659461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1540719504 + 108847489 = 39252^2 + 10433^2 .

It is an emirp because it is prime and its reverse (3996659461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1649566993 - 2¹ = 1649566991 is a prime.

Together with 1649566991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1649566991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824783496 + 824783497.

It is an arithmetic number, because the mean of its divisors is an integer number (824783497).

Almost surely, 2^1649566993 is an apocalyptic number.

It is an amenable number.

1649566993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649566993 is an equidigital number, since it uses as much as digits as its factorization.

1649566993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9447840, while the sum is 58.

The square root of 1649566993 is about 40614.8617257279. The cubic root of 1649566993 is about 1181.5623738398.

The spelling of 1649566993 in words is "one billion, six hundred forty-nine million, five hundred sixty-six thousand, nine hundred ninety-three".