661222667 has 32 divisors (see below), whose sum is σ = 850291200. Its totient is φ = 500525568.

The previous prime is 661222663. The next prime is 661222687. The reversal of 661222667 is 766222166.

It is a cyclic number.

It is not a de Polignac number, because 661222667 - 2² = 661222663 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661222667.

It is not an unprimeable number, because it can be changed into a prime (661222663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 245108 + ... + 247790.

It is an arithmetic number, because the mean of its divisors is an integer number (26571600).

Almost surely, 2^661222667 is an apocalyptic number.

661222667 is a deficient number, since it is larger than the sum of its proper divisors (189068533).

661222667 is a wasteful number, since it uses less digits than its factorization.

661222667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2835.

The product of its digits is 72576, while the sum is 38.

The square root of 661222667 is about 25714.2502710073. The cubic root of 661222667 is about 871.1960767270.

The spelling of 661222667 in words is "six hundred sixty-one million, two hundred twenty-two thousand, six hundred sixty-seven".