66666591461 has 2 divisors, whose sum is σ = 66666591462. Its totient is φ = 66666591460.

The previous prime is 66666591443. The next prime is 66666591493. The reversal of 66666591461 is 16419566666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66620772100 + 45819361 = 258110^2 + 6769^2 .

It is a cyclic number.

It is not a de Polignac number, because 66666591461 - 2¹⁰ = 66666590437 is a prime.

It is a super-2 number, since 2×66666591461² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66666591397 and 66666591406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66666597461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333295730 + 33333295731.

It is an arithmetic number, because the mean of its divisors is an integer number (33333295731).

Almost surely, 2^66666591461 is an apocalyptic number.

It is an amenable number.

66666591461 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666591461 is an equidigital number, since it uses as much as digits as its factorization.

66666591461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8398080, while the sum is 56.

The spelling of 66666591461 in words is "sixty-six billion, six hundred sixty-six million, five hundred ninety-one thousand, four hundred sixty-one".