6997257398640 has 80 divisors (see below), whose sum is σ = 21692264427648. Its totient is φ = 1865869371648.

The previous prime is 6997257398633. The next prime is 6997257398687. The reversal of 6997257398640 is 468937527996.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×6997257398640² (a number of 26 digits) contains 22 as substring.

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, 6488967 + ... + 7490073.

Almost surely, 2^{6997257398640} is an apocalyptic number.

6997257398640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6997257398640 is an abundant number, since it is smaller than the sum of its proper divisors (14695007029008).

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

6997257398640 is a wasteful number, since it uses less digits than its factorization.

6997257398640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030246 (or 1030240 counting only the distinct ones).

The product of its (nonzero) digits is 1234517760, while the sum is 75.

The spelling of 6997257398640 in words is "six trillion, nine hundred ninety-seven billion, two hundred fifty-seven million, three hundred ninety-eight thousand, six hundred forty".