21061747200 has 480 divisors, whose sum is σ = 77402045952. Its totient is φ = 5013504000.

The previous prime is 21061747153. The next prime is 21061747211. The reversal of 21061747200 is 274716012.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15474520 + ... + 15475880.

Almost surely, 2^21061747200 is an apocalyptic number.

21061747200 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 21061747200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38701022976).

21061747200 is an abundant number, since it is smaller than the sum of its proper divisors (56340298752).

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

21061747200 is a wasteful number, since it uses less digits than its factorization.

21061747200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1436 (or 1415 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The spelling of 21061747200 in words is "twenty-one billion, sixty-one million, seven hundred forty-seven thousand, two hundred".