641657970 has 64 divisors (see below), whose sum is σ = 1718922240. Its totient is φ = 170325504.

The previous prime is 641657953. The next prime is 641657983. The reversal of 641657970 is 79756146.

It is a happy number.

641657970 is a `hidden beast` number, since 6 + 4 + 1 + 6 + 579 + 70 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54882 + ... + 65538.

It is an arithmetic number, because the mean of its divisors is an integer number (26858160).

Almost surely, 2^641657970 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641657970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (859461120).

641657970 is an abundant number, since it is smaller than the sum of its proper divisors (1077264270).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

641657970 is a wasteful number, since it uses less digits than its factorization.

641657970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10896 (or 10890 counting only the distinct ones).

The product of its (nonzero) digits is 317520, while the sum is 45.

The square root of 641657970 is about 25330.9685957723. The cubic root of 641657970 is about 862.5173985148.

The spelling of 641657970 in words is "six hundred forty-one million, six hundred fifty-seven thousand, nine hundred seventy".