661225867 has 4 divisors (see below), whose sum is σ = 667405656. Its totient is φ = 655046080.

The previous prime is 661225861. The next prime is 661225879. The reversal of 661225867 is 768522166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 768522166 = 2 ⋅384261083.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661225867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661225861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3089734 + ... + 3089947.

It is an arithmetic number, because the mean of its divisors is an integer number (166851414).

Almost surely, 2^661225867 is an apocalyptic number.

661225867 is a deficient number, since it is larger than the sum of its proper divisors (6179789).

661225867 is a wasteful number, since it uses less digits than its factorization.

661225867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6179788.

The product of its digits is 241920, while the sum is 43.

The square root of 661225867 is about 25714.3124932400. The cubic root of 661225867 is about 871.1974821149.

The spelling of 661225867 in words is "six hundred sixty-one million, two hundred twenty-five thousand, eight hundred sixty-seven".