646215801 has 96 divisors (see below), whose sum is σ = 1153087488. Its totient is φ = 312480000.

The previous prime is 646215763. The next prime is 646215809. The reversal of 646215801 is 108512646.

It is not a de Polignac number, because 646215801 - 2¹⁴ = 646199417 is a prime.

It is a super-2 number, since 2×646215801² = 835189722924143202, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (646215809) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9101596 + ... + 9101666.

It is an arithmetic number, because the mean of its divisors is an integer number (12011328).

Almost surely, 2^646215801 is an apocalyptic number.

It is an amenable number.

646215801 is a deficient number, since it is larger than the sum of its proper divisors (506871687).

646215801 is a wasteful number, since it uses less digits than its factorization.

646215801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195 (or 164 counting only the distinct ones).

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

The square root of 646215801 is about 25420.7749881863. The cubic root of 646215801 is about 864.5547960137.

The spelling of 646215801 in words is "six hundred forty-six million, two hundred fifteen thousand, eight hundred one".