1645431345 has 12 divisors (see below), whose sum is σ = 2852081076. Its totient is φ = 877563360.

The previous prime is 1645431313. The next prime is 1645431391. The reversal of 1645431345 is 5431345461.

1645431345 is a `hidden beast` number, since 1 + 64 + 543 + 13 + 45 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1293193521 + 352237824 = 35961^2 + 18768^2 .

It is not a de Polignac number, because 1645431345 - 2⁵ = 1645431313 is a prime.

It is a super-2 number, since 2×1645431345² = 5414888622217018050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18282526 + ... + 18282615.

It is an arithmetic number, because the mean of its divisors is an integer number (237673423).

Almost surely, 2^1645431345 is an apocalyptic number.

1645431345 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1645431345 is a deficient number, since it is larger than the sum of its proper divisors (1206649731).

1645431345 is a wasteful number, since it uses less digits than its factorization.

1645431345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36565152 (or 36565149 counting only the distinct ones).

The product of its digits is 86400, while the sum is 36.

The square root of 1645431345 is about 40563.9167857346. The cubic root of 1645431345 is about 1180.5741113696.

The spelling of 1645431345 in words is "one billion, six hundred forty-five million, four hundred thirty-one thousand, three hundred forty-five".