26497457640 has 256 divisors, whose sum is σ = 89268480000. Its totient is φ = 6991017984.

The previous prime is 26497457633. The next prime is 26497457641. The reversal of 26497457640 is 4675479462.

26497457640 is a `hidden beast` number, since 2 + 6 + 497 + 45 + 76 + 40 = 666.

It is a super-2 number, since 2×26497457640² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (26497457641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 64785756 + ... + 64786164.

It is an arithmetic number, because the mean of its divisors is an integer number (348705000).

Almost surely, 2^26497457640 is an apocalyptic number.

26497457640 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 26497457640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44634240000).

26497457640 is an abundant number, since it is smaller than the sum of its proper divisors (62771022360).

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

26497457640 is a wasteful number, since it uses less digits than its factorization.

26497457640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921 (or 911 counting only the distinct ones).

The product of its (nonzero) digits is 10160640, while the sum is 54.

The spelling of 26497457640 in words is "twenty-six billion, four hundred ninety-seven million, four hundred fifty-seven thousand, six hundred forty".