641261501 has 4 divisors (see below), whose sum is σ = 652130400. Its totient is φ = 630392604.

The previous prime is 641261479. The next prime is 641261503. The reversal of 641261501 is 105162146.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 641261501 - 2¹⁸ = 640999357 is a prime.

It is a super-3 number, since 3×641261501³ (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 not an unprimeable number, because it can be changed into a prime (641261503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5434361 + ... + 5434478.

It is an arithmetic number, because the mean of its divisors is an integer number (163032600).

Almost surely, 2^641261501 is an apocalyptic number.

It is an amenable number.

641261501 is a deficient number, since it is larger than the sum of its proper divisors (10868899).

641261501 is a wasteful number, since it uses less digits than its factorization.

641261501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10868898.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 641261501 is about 25323.1416099978. The cubic root of 641261501 is about 862.3397172156.

The spelling of 641261501 in words is "six hundred forty-one million, two hundred sixty-one thousand, five hundred one".