661352463564 has 192 divisors, whose sum is σ = 1823899908096. Its totient is φ = 184647868416.

The previous prime is 661352463553. The next prime is 661352463571. The reversal of 661352463564 is 465364253166.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8311552 + ... + 8390744.

It is an arithmetic number, because the mean of its divisors is an integer number (9499478688).

Almost surely, 2^661352463564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661352463564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (911949954048).

661352463564 is an abundant number, since it is smaller than the sum of its proper divisors (1162547444532).

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

661352463564 is a wasteful number, since it uses less digits than its factorization.

661352463564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79344 (or 79342 counting only the distinct ones).

The product of its digits is 9331200, while the sum is 51.

The spelling of 661352463564 in words is "six hundred sixty-one billion, three hundred fifty-two million, four hundred sixty-three thousand, five hundred sixty-four".