661613653470 has 128 divisors (see below), whose sum is σ = 1987574464512. Its totient is φ = 136930320000.

The previous prime is 661613653469. The next prime is 661613653537. The reversal of 661613653470 is 74356316166.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9267 + ... + 1150353.

It is an arithmetic number, because the mean of its divisors is an integer number (15527925504).

Almost surely, 2^661613653470 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661613653470, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993787232256).

661613653470 is an abundant number, since it is smaller than the sum of its proper divisors (1325960811042).

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

661613653470 is a wasteful number, since it uses less digits than its factorization.

661613653470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1141366.

The product of its (nonzero) digits is 1632960, while the sum is 48.

The spelling of 661613653470 in words is "six hundred sixty-one billion, six hundred thirteen million, six hundred fifty-three thousand, four hundred seventy".