26664491566 has 4 divisors (see below), whose sum is σ = 39996737352. Its totient is φ = 13332245782.

The previous prime is 26664491533. The next prime is 26664491599. The reversal of 26664491566 is 66519446662.

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

It is an interprime number because it is at equal distance from previous prime (26664491533) and next prime (26664491599).

It is a super-2 number, since 2×26664491566² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 6666122890 + ... + 6666122893.

It is an arithmetic number, because the mean of its divisors is an integer number (9999184338).

Almost surely, 2^26664491566 is an apocalyptic number.

26664491566 is a deficient number, since it is larger than the sum of its proper divisors (13332245786).

26664491566 is a wasteful number, since it uses less digits than its factorization.

26664491566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13332245785.

The product of its digits is 11197440, while the sum is 55.

The spelling of 26664491566 in words is "twenty-six billion, six hundred sixty-four million, four hundred ninety-one thousand, five hundred sixty-six".