645235641 has 12 divisors (see below), whose sum is σ = 932272432. Its totient is φ = 430034616.

The previous prime is 645235607. The next prime is 645235651. The reversal of 645235641 is 146532546.

645235641 is a `hidden beast` number, since 6 + 4 + 5 + 2 + 3 + 5 + 641 = 666.

It is not a de Polignac number, because 645235641 - 2¹¹ = 645233593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645235596 and 645235605.

It is not an unprimeable number, because it can be changed into a prime (645235651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32610 + ... + 48516.

Almost surely, 2^645235641 is an apocalyptic number.

It is an amenable number.

645235641 is a deficient number, since it is larger than the sum of its proper divisors (287036791).

645235641 is a wasteful number, since it uses less digits than its factorization.

645235641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20420 (or 20417 counting only the distinct ones).

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

The square root of 645235641 is about 25401.4889524217. The cubic root of 645235641 is about 864.1174649000.

The spelling of 645235641 in words is "six hundred forty-five million, two hundred thirty-five thousand, six hundred forty-one".