645777101 has 8 divisors (see below), whose sum is σ = 669501504. Its totient is φ = 622432480.

The previous prime is 645777061. The next prime is 645777127. The reversal of 645777101 is 101777546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645777101 - 2¹⁸ = 645514957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645777161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91481 + ... + 98286.

It is an arithmetic number, because the mean of its divisors is an integer number (83687688).

Almost surely, 2^645777101 is an apocalyptic number.

It is an amenable number.

645777101 is a deficient number, since it is larger than the sum of its proper divisors (23724403).

645777101 is a wasteful number, since it uses less digits than its factorization.

645777101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189891.

The product of its (nonzero) digits is 41160, while the sum is 38.

The square root of 645777101 is about 25412.1447540344. The cubic root of 645777101 is about 864.3591100686.

The spelling of 645777101 in words is "six hundred forty-five million, seven hundred seventy-seven thousand, one hundred one".