66461556656455 has 4 divisors (see below), whose sum is σ = 79753867987752. Its totient is φ = 53169245325160.

The previous prime is 66461556656437. The next prime is 66461556656479. The reversal of 66461556656455 is 55465665516466.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 66461556656455 - 2²¹ = 66461554559303 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6646155665641 + ... + 6646155665650.

It is an arithmetic number, because the mean of its divisors is an integer number (19938466996938).

Almost surely, 2^{66461556656455} is an apocalyptic number.

66461556656455 is a deficient number, since it is larger than the sum of its proper divisors (13292311331297).

66461556656455 is a wasteful number, since it uses less digits than its factorization.

66461556656455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13292311331296.

The product of its digits is 2332800000, while the sum is 70.

The spelling of 66461556656455 in words is "sixty-six trillion, four hundred sixty-one billion, five hundred fifty-six million, six hundred fifty-six thousand, four hundred fifty-five".