8400724645 has 4 divisors (see below), whose sum is σ = 10080869580. Its totient is φ = 6720579712.

The previous prime is 8400724601. The next prime is 8400724679. The reversal of 8400724645 is 5464270048.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4667759041 + 3732965604 = 68321^2 + 61098^2 .

It is a cyclic number.

It is not a de Polignac number, because 8400724645 - 2¹⁵ = 8400691877 is a prime.

It is a super-2 number, since 2×8400724645² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 8400724598 and 8400724607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 840072460 + ... + 840072469.

It is an arithmetic number, because the mean of its divisors is an integer number (2520217395).

Almost surely, 2^8400724645 is an apocalyptic number.

It is an amenable number.

8400724645 is a deficient number, since it is larger than the sum of its proper divisors (1680144935).

8400724645 is a wasteful number, since it uses less digits than its factorization.

8400724645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680144934.

The product of its (nonzero) digits is 215040, while the sum is 40.

The square root of 8400724645 is about 91655.4670764379. The cubic root of 8400724645 is about 2032.8511664360.

The spelling of 8400724645 in words is "eight billion, four hundred million, seven hundred twenty-four thousand, six hundred forty-five".