661272223 has 2 divisors, whose sum is σ = 661272224. Its totient is φ = 661272222.

The previous prime is 661272217. The next prime is 661272277. The reversal of 661272223 is 322272166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661272223 - 2²¹ = 659175071 is a prime.

It is a super-2 number, since 2×661272223² = 874561905822723458, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661272323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330636111 + 330636112.

It is an arithmetic number, because the mean of its divisors is an integer number (330636112).

Almost surely, 2^661272223 is an apocalyptic number.

661272223 is a deficient number, since it is larger than the sum of its proper divisors (1).

661272223 is an equidigital number, since it uses as much as digits as its factorization.

661272223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 31.

The square root of 661272223 is about 25715.2138431707. The cubic root of 661272223 is about 871.2178404064.

The spelling of 661272223 in words is "six hundred sixty-one million, two hundred seventy-two thousand, two hundred twenty-three".