1564674997 has 4 divisors (see below), whose sum is σ = 1615148416. Its totient is φ = 1514201580.

The previous prime is 1564674983. The next prime is 1564675001. The reversal of 1564674997 is 7994764651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7994764651 = 439 ⋅18211309.

It is a cyclic number.

It is not a de Polignac number, because 1564674997 - 2²⁷ = 1430457269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1564674967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25236663 + ... + 25236724.

It is an arithmetic number, because the mean of its divisors is an integer number (403787104).

Almost surely, 2^1564674997 is an apocalyptic number.

It is an amenable number.

1564674997 is a deficient number, since it is larger than the sum of its proper divisors (50473419).

1564674997 is an equidigital number, since it uses as much as digits as its factorization.

1564674997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50473418.

The product of its digits is 11430720, while the sum is 58.

The square root of 1564674997 is about 39555.9729623732. The cubic root of 1564674997 is about 1160.9353823301.

The spelling of 1564674997 in words is "one billion, five hundred sixty-four million, six hundred seventy-four thousand, nine hundred ninety-seven".