641961854 has 32 divisors (see below), whose sum is σ = 1088030880. Its totient is φ = 282258432.

The previous prime is 641961847. The next prime is 641961863. The reversal of 641961854 is 458169146.

It is a super-2 number, since 2×641961854² = 824230043982234632, which contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 40352 + ... + 53964.

It is an arithmetic number, because the mean of its divisors is an integer number (34000965).

Almost surely, 2^641961854 is an apocalyptic number.

641961854 is a deficient number, since it is larger than the sum of its proper divisors (446069026).

641961854 is a wasteful number, since it uses less digits than its factorization.

641961854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13724.

The product of its digits is 207360, while the sum is 44.

The square root of 641961854 is about 25336.9661561916. The cubic root of 641961854 is about 862.6535374358.

The spelling of 641961854 in words is "six hundred forty-one million, nine hundred sixty-one thousand, eight hundred fifty-four".