661548782 has 32 divisors (see below), whose sum is σ = 1040183424. Its totient is φ = 315302400.

The previous prime is 661548781. The next prime is 661548791. The reversal of 661548782 is 287845166.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661548781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 647432 + ... + 648452.

It is an arithmetic number, because the mean of its divisors is an integer number (32505732).

Almost surely, 2^661548782 is an apocalyptic number.

661548782 is a deficient number, since it is larger than the sum of its proper divisors (378634642).

661548782 is a wasteful number, since it uses less digits than its factorization.

661548782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244.

The product of its digits is 645120, while the sum is 47.

The square root of 661548782 is about 25720.5906230786. The cubic root of 661548782 is about 871.3392778139.

The spelling of 661548782 in words is "six hundred sixty-one million, five hundred forty-eight thousand, seven hundred eighty-two".