645216801 has 16 divisors (see below), whose sum is σ = 907987200. Its totient is φ = 406416528.

The previous prime is 645216797. The next prime is 645216811. The reversal of 645216801 is 108612546.

It is not a de Polignac number, because 645216801 - 2² = 645216797 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645216811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6670 + ... + 36536.

It is an arithmetic number, because the mean of its divisors is an integer number (56749200).

Almost surely, 2^645216801 is an apocalyptic number.

It is an amenable number.

645216801 is a deficient number, since it is larger than the sum of its proper divisors (262770399).

645216801 is a wasteful number, since it uses less digits than its factorization.

645216801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30268.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 645216801 is about 25401.1181053118. The cubic root of 645216801 is about 864.1090544680.

The spelling of 645216801 in words is "six hundred forty-five million, two hundred sixteen thousand, eight hundred one".