641506021 has 8 divisors (see below), whose sum is σ = 691061504. Its totient is φ = 591980400.

The previous prime is 641506009. The next prime is 641506027. The reversal of 641506021 is 120605146.

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

It is a cyclic number.

It is not a de Polignac number, because 641506021 - 2¹⁵ = 641473253 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 (641506027) 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, 59380 + ... + 69346.

It is an arithmetic number, because the mean of its divisors is an integer number (86382688).

Almost surely, 2^641506021 is an apocalyptic number.

It is an amenable number.

641506021 is a deficient number, since it is larger than the sum of its proper divisors (49555483).

641506021 is a wasteful number, since it uses less digits than its factorization.

641506021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14931.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 641506021 is about 25327.9691448012. The cubic root of 641506021 is about 862.4493097984.

The spelling of 641506021 in words is "six hundred forty-one million, five hundred six thousand, twenty-one".