661230211357 has 2 divisors, whose sum is σ = 661230211358. Its totient is φ = 661230211356.

The previous prime is 661230211339. The next prime is 661230211403. The reversal of 661230211357 is 753112032166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 580653144036 + 80577067321 = 762006^2 + 283861^2 .

It is a cyclic number.

It is not a de Polignac number, because 661230211357 - 2²⁷ = 661095993629 is a prime.

It is a super-2 number, since 2×661230211357² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661230211457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330615105678 + 330615105679.

It is an arithmetic number, because the mean of its divisors is an integer number (330615105679).

Almost surely, 2^661230211357 is an apocalyptic number.

It is an amenable number.

661230211357 is a deficient number, since it is larger than the sum of its proper divisors (1).

661230211357 is an equidigital number, since it uses as much as digits as its factorization.

661230211357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 37.

The spelling of 661230211357 in words is "six hundred sixty-one billion, two hundred thirty million, two hundred eleven thousand, three hundred fifty-seven".