21381573730 has 16 divisors (see below), whose sum is σ = 41985635904. Its totient is φ = 7775117680.

The previous prime is 21381573709. The next prime is 21381573779. The reversal of 21381573730 is 3737518312.

It is a super-2 number, since 2×21381573730² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97188862 + ... + 97189081.

It is an arithmetic number, because the mean of its divisors is an integer number (2624102244).

Almost surely, 2^21381573730 is an apocalyptic number.

21381573730 is a deficient number, since it is larger than the sum of its proper divisors (20604062174).

21381573730 is a wasteful number, since it uses less digits than its factorization.

21381573730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194377961.

The product of its (nonzero) digits is 105840, while the sum is 40.

The spelling of 21381573730 in words is "twenty-one billion, three hundred eighty-one million, five hundred seventy-three thousand, seven hundred thirty".