26640507264 has 128 divisors (see below), whose sum is σ = 80932577280. Its totient is φ = 7605964800.

The previous prime is 26640507211. The next prime is 26640507277. The reversal of 26640507264 is 46270504662.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4838337 + ... + 4843839.

It is an arithmetic number, because the mean of its divisors is an integer number (632285760).

Almost surely, 2^26640507264 is an apocalyptic number.

26640507264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 26640507264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40466288640).

26640507264 is an abundant number, since it is smaller than the sum of its proper divisors (54292070016).

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

26640507264 is a wasteful number, since it uses less digits than its factorization.

26640507264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7328 (or 7316 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 42.

The spelling of 26640507264 in words is "twenty-six billion, six hundred forty million, five hundred seven thousand, two hundred sixty-four".