661464251 has 8 divisors (see below), whose sum is σ = 763444704. Its totient is φ = 561355200.

The previous prime is 661464247. The next prime is 661464253. The reversal of 661464251 is 152464166.

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

It is not a de Polignac number, because 661464251 - 2² = 661464247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661464253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 467090 + ... + 468503.

It is an arithmetic number, because the mean of its divisors is an integer number (95430588).

Almost surely, 2^661464251 is an apocalyptic number.

661464251 is a deficient number, since it is larger than the sum of its proper divisors (101980453).

661464251 is a wasteful number, since it uses less digits than its factorization.

661464251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 935701.

The product of its digits is 34560, while the sum is 35.

The square root of 661464251 is about 25718.9473151605. The cubic root of 661464251 is about 871.3021637366.

The spelling of 661464251 in words is "six hundred sixty-one million, four hundred sixty-four thousand, two hundred fifty-one".