660164045621 has 2 divisors, whose sum is σ = 660164045622. Its totient is φ = 660164045620.

The previous prime is 660164045573. The next prime is 660164045633. The reversal of 660164045621 is 126540461066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631540143025 + 28623902596 = 794695^2 + 169186^2 .

It is a cyclic number.

It is not a de Polignac number, because 660164045621 - 2²² = 660159851317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660164005621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330082022810 + 330082022811.

It is an arithmetic number, because the mean of its divisors is an integer number (330082022811).

Almost surely, 2^660164045621 is an apocalyptic number.

It is an amenable number.

660164045621 is a deficient number, since it is larger than the sum of its proper divisors (1).

660164045621 is an equidigital number, since it uses as much as digits as its factorization.

660164045621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 660164045621 in words is "six hundred sixty billion, one hundred sixty-four million, forty-five thousand, six hundred twenty-one".