646997901 has 8 divisors (see below), whose sum is σ = 941087904. Its totient is φ = 392119920.

The previous prime is 646997893. The next prime is 646997921. The reversal of 646997901 is 109799646.

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

It is not a de Polignac number, because 646997901 - 2³ = 646997893 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646997921) 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, 9802966 + ... + 9803031.

It is an arithmetic number, because the mean of its divisors is an integer number (117635988).

Almost surely, 2^646997901 is an apocalyptic number.

It is an amenable number.

646997901 is a deficient number, since it is larger than the sum of its proper divisors (294090003).

646997901 is a wasteful number, since it uses less digits than its factorization.

646997901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19606011.

The product of its (nonzero) digits is 734832, while the sum is 51.

The square root of 646997901 is about 25436.1534238178. The cubic root of 646997901 is about 864.9034389411.

The spelling of 646997901 in words is "six hundred forty-six million, nine hundred ninety-seven thousand, nine hundred one".