21797187692544 has 480 divisors, whose sum is σ = 71077291084800. Its totient is φ = 6600378286080.

The previous prime is 21797187692531. The next prime is 21797187692561. The reversal of 21797187692544 is 44529678179712.

21797187692544 is a `hidden beast` number, since 2 + 1 + 7 + 9 + 7 + 1 + 8 + 76 + 9 + 2 + 544 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

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, 3096627777 + ... + 3096634815.

It is an arithmetic number, because the mean of its divisors is an integer number (148077689760).

Almost surely, 2^{21797187692544} is an apocalyptic number.

21797187692544 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 21797187692544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35538645542400).

21797187692544 is an abundant number, since it is smaller than the sum of its proper divisors (49280103392256).

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

21797187692544 is a wasteful number, since it uses less digits than its factorization.

21797187692544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8781 (or 8752 counting only the distinct ones).

The product of its digits is 426746880, while the sum is 72.

The spelling of 21797187692544 in words is "twenty-one trillion, seven hundred ninety-seven billion, one hundred eighty-seven million, six hundred ninety-two thousand, five hundred forty-four".