641641655 has 16 divisors (see below), whose sum is σ = 775142784. Its totient is φ = 509878560.

The previous prime is 641641639. The next prime is 641641667. The reversal of 641641655 is 556146146.

It is a happy number.

It is not a de Polignac number, because 641641655 - 2⁴ = 641641639 is a prime.

It is a super-3 number, since 3×641641655³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

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, 660320 + ... + 661290.

It is an arithmetic number, because the mean of its divisors is an integer number (48446424).

Almost surely, 2^641641655 is an apocalyptic number.

641641655 is a deficient number, since it is larger than the sum of its proper divisors (133501129).

641641655 is a wasteful number, since it uses less digits than its factorization.

641641655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1726.

The product of its digits is 86400, while the sum is 38.

The square root of 641641655 is about 25330.6465570857. The cubic root of 641641655 is about 862.5100882388.

The spelling of 641641655 in words is "six hundred forty-one million, six hundred forty-one thousand, six hundred fifty-five".