21198774240 has 864 divisors, whose sum is σ = 92688261120. Its totient is φ = 4309106688.

The previous prime is 21198774239. The next prime is 21198774319. The reversal of 21198774240 is 4247789112.

21198774240 is a `hidden beast` number, since 211 + 9 + 8 + 7 + 7 + 424 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 55349089 + ... + 55349471.

It is an arithmetic number, because the mean of its divisors is an integer number (107278080).

Almost surely, 2^21198774240 is an apocalyptic number.

21198774240 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 21198774240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46344130560).

21198774240 is an abundant number, since it is smaller than the sum of its proper divisors (71489486880).

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

21198774240 is a wasteful number, since it uses less digits than its factorization.

21198774240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464 (or 436 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The spelling of 21198774240 in words is "twenty-one billion, one hundred ninety-eight million, seven hundred seventy-four thousand, two hundred forty".