21534200730 has 448 divisors, whose sum is σ = 71302353408. Its totient is φ = 4568555520.

The previous prime is 21534200659. The next prime is 21534200759. The reversal of 21534200730 is 3700243512.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21534200694 and 21534200703.

It is an unprimeable number.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 89353410 + ... + 89353650.

Almost surely, 2^21534200730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21534200730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35651176704).

21534200730 is an abundant number, since it is smaller than the sum of its proper divisors (49768152678).

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

21534200730 is a wasteful number, since it uses less digits than its factorization.

21534200730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 27.

The spelling of 21534200730 in words is "twenty-one billion, five hundred thirty-four million, two hundred thousand, seven hundred thirty".