661641554154 has 32 divisors (see below), whose sum is σ = 1513131166080. Its totient is φ = 188939492352.

The previous prime is 661641554149. The next prime is 661641554207. The reversal of 661641554154 is 451455146166.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 4126719 + ... + 4284050.

It is an arithmetic number, because the mean of its divisors is an integer number (47285348940).

Almost surely, 2^661641554154 is an apocalyptic number.

661641554154 is an abundant number, since it is smaller than the sum of its proper divisors (851489611926).

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

661641554154 is a wasteful number, since it uses less digits than its factorization.

661641554154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8412654.

The product of its digits is 1728000, while the sum is 48.

The spelling of 661641554154 in words is "six hundred sixty-one billion, six hundred forty-one million, five hundred fifty-four thousand, one hundred fifty-four".