645073755 has 32 divisors (see below), whose sum is σ = 1140355584. Its totient is φ = 309720576.

The previous prime is 645073753. The next prime is 645073757. The reversal of 645073755 is 557370546.

It is an interprime number because it is at equal distance from previous prime (645073753) and next prime (645073757).

It is not a de Polignac number, because 645073755 - 2¹ = 645073753 is a prime.

It is a super-2 number, since 2×645073755² = 832240298779600050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645073753) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49129 + ... + 60858.

It is an arithmetic number, because the mean of its divisors is an integer number (35636112).

Almost surely, 2^645073755 is an apocalyptic number.

645073755 is a deficient number, since it is larger than the sum of its proper divisors (495281829).

645073755 is a wasteful number, since it uses less digits than its factorization.

645073755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110035.

The product of its (nonzero) digits is 441000, while the sum is 42.

The square root of 645073755 is about 25398.3022070374. The cubic root of 645073755 is about 864.0451914484.

The spelling of 645073755 in words is "six hundred forty-five million, seventy-three thousand, seven hundred fifty-five".