661501646 has 8 divisors (see below), whose sum is σ = 1068579624. Its totient is φ = 305308440.

The previous prime is 661501627. The next prime is 661501693. The reversal of 661501646 is 646105166.

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

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 12721160 + ... + 12721211.

It is an arithmetic number, because the mean of its divisors is an integer number (133572453).

Almost surely, 2^661501646 is an apocalyptic number.

661501646 is a deficient number, since it is larger than the sum of its proper divisors (407077978).

661501646 is a wasteful number, since it uses less digits than its factorization.

661501646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25442386.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 661501646 is about 25719.6742980933. The cubic root of 661501646 is about 871.3185827294.

The spelling of 661501646 in words is "six hundred sixty-one million, five hundred one thousand, six hundred forty-six".