661644754 has 8 divisors (see below), whose sum is σ = 993000960. Its totient is φ = 330644436.

The previous prime is 661644751. The next prime is 661644761. The reversal of 661644754 is 457446166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 661644754.

It is not an unprimeable number, because it can be changed into a prime (661644751) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 84274 + ... + 91789.

It is an arithmetic number, because the mean of its divisors is an integer number (124125120).

Almost surely, 2^661644754 is an apocalyptic number.

661644754 is a deficient number, since it is larger than the sum of its proper divisors (331356206).

661644754 is a wasteful number, since it uses less digits than its factorization.

661644754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177944.

The product of its digits is 483840, while the sum is 43.

The square root of 661644754 is about 25722.4562201979. The cubic root of 661644754 is about 871.3814113304.

The spelling of 661644754 in words is "six hundred sixty-one million, six hundred forty-four thousand, seven hundred fifty-four".