26640243840 has 256 divisors, whose sum is σ = 97793879040. Its totient is φ = 6042316800.

The previous prime is 26640243829. The next prime is 26640243857. The reversal of 26640243840 is 4834204662.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1753075 + ... + 1768205.

It is an arithmetic number, because the mean of its divisors is an integer number (382007340).

Almost surely, 2^26640243840 is an apocalyptic number.

26640243840 is a gapful number since it is divisible by the number (20) 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 26640243840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48896939520).

26640243840 is an abundant number, since it is smaller than the sum of its proper divisors (71153635200).

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

26640243840 is a wasteful number, since it uses less digits than its factorization.

26640243840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15291 (or 15279 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 39.

It can be divided in two parts, 26640 and 243840, that added together give a triangular number (270480 = T₇₃₅).

The spelling of 26640243840 in words is "twenty-six billion, six hundred forty million, two hundred forty-three thousand, eight hundred forty".