815134891645 has 16 divisors (see below), whose sum is σ = 985054722480. Its totient is φ = 647518270464.

The previous prime is 815134891631. The next prime is 815134891667. The reversal of 815134891645 is 546198431518.

It can be written as a sum of positive squares in 8 ways, for example, as 69153746841 + 745981144804 = 262971^2 + 863702^2 .

It is a cyclic number.

It is not a de Polignac number, because 815134891645 - 2⁷ = 815134891517 is a prime.

It is a super-3 number, since 3×815134891645³ (a number of 37 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 820179 + ... + 1517551.

It is an arithmetic number, because the mean of its divisors is an integer number (61565920155).

Almost surely, 2^815134891645 is an apocalyptic number.

It is an amenable number.

815134891645 is a deficient number, since it is larger than the sum of its proper divisors (169919830835).

815134891645 is a wasteful number, since it uses less digits than its factorization.

815134891645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699024.

The product of its digits is 4147200, while the sum is 55.

The spelling of 815134891645 in words is "eight hundred fifteen billion, one hundred thirty-four million, eight hundred ninety-one thousand, six hundred forty-five".