21490709760 has 216 divisors, whose sum is σ = 80075838024. Its totient is φ = 5289984000.

The previous prime is 21490709759. The next prime is 21490709803. The reversal of 21490709760 is 6790709412.

21490709760 is a `hidden beast` number, since 2 + 1 + 490 + 70 + 97 + 6 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 379782144 + 21110927616 = 19488^2 + 145296^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78010 + ... + 221510.

Almost surely, 2^21490709760 is an apocalyptic number.

21490709760 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 21490709760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40037919012).

21490709760 is an abundant number, since it is smaller than the sum of its proper divisors (58585128264).

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

21490709760 is a wasteful number, since it uses less digits than its factorization.

21490709760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143541 (or 143524 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The spelling of 21490709760 in words is "twenty-one billion, four hundred ninety million, seven hundred nine thousand, seven hundred sixty".