26666821641780 has 72 divisors (see below), whose sum is σ = 80893786506624. Its totient is φ = 7110763204800.

The previous prime is 26666821641743. The next prime is 26666821641787. The reversal of 26666821641780 is 8714612866662.

It is a happy number.

It is a super-2 number, since 2×26666821641780² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26666821641787) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 749376 + ... + 7341335.

It is an arithmetic number, because the mean of its divisors is an integer number (1123524812592).

Almost surely, 2^{26666821641780} is an apocalyptic number.

26666821641780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

26666821641780 is an abundant number, since it is smaller than the sum of its proper divisors (54226964864844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

26666821641780 is a wasteful number, since it uses less digits than its factorization.

26666821641780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8109037 (or 8109032 counting only the distinct ones).

The product of its (nonzero) digits is 55738368, while the sum is 63.

The spelling of 26666821641780 in words is "twenty-six trillion, six hundred sixty-six billion, eight hundred twenty-one million, six hundred forty-one thousand, seven hundred eighty".