641211660 has 48 divisors (see below), whose sum is σ = 1994882400. Its totient is φ = 170989632.

The previous prime is 641211653. The next prime is 641211671. The reversal of 641211660 is 66112146.

641211660 is a `hidden beast` number, since 641 + 2 + 1 + 16 + 6 + 0 = 666.

It is a super-2 number, since 2×641211660² = 822304785839911200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 593175 + ... + 594254.

It is an arithmetic number, because the mean of its divisors is an integer number (41560050).

Almost surely, 2^641211660 is an apocalyptic number.

641211660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

641211660 is an abundant number, since it is smaller than the sum of its proper divisors (1353670740).

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

641211660 is a wasteful number, since it uses less digits than its factorization.

641211660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1187447 (or 1187439 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 641211660 is about 25322.1574910196. The cubic root of 641211660 is about 862.3173753227.

The spelling of 641211660 in words is "six hundred forty-one million, two hundred eleven thousand, six hundred sixty".