21497637401280 has 280 divisors, whose sum is σ = 76478217599520. Its totient is φ = 5732153118720.

The previous prime is 21497637401213. The next prime is 21497637401293. The reversal of 21497637401280 is 8210473679412.

21497637401280 is a `hidden beast` number, since 2 + 1 + 497 + 6 + 3 + 74 + 0 + 1 + 2 + 80 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 319534045 + ... + 319601315.

Almost surely, 2^{21497637401280} is an apocalyptic number.

21497637401280 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 21497637401280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38239108799760).

21497637401280 is an abundant number, since it is smaller than the sum of its proper divisors (54980580198240).

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

21497637401280 is a wasteful number, since it uses less digits than its factorization.

21497637401280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79629 (or 79610 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 54.

The spelling of 21497637401280 in words is "twenty-one trillion, four hundred ninety-seven billion, six hundred thirty-seven million, four hundred one thousand, two hundred eighty".