21530321716 has 12 divisors (see below), whose sum is σ = 37679241600. Its totient is φ = 10764824120.

The previous prime is 21530321671. The next prime is 21530321737. The reversal of 21530321716 is 61712303512.

It is a happy number.

It is a super-2 number, since 2×21530321716² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108861 + ... + 234331.

It is an arithmetic number, because the mean of its divisors is an integer number (3139936800).

Almost surely, 2^21530321716 is an apocalyptic number.

It is an amenable number.

21530321716 is a deficient number, since it is larger than the sum of its proper divisors (16148919884).

21530321716 is a wasteful number, since it uses less digits than its factorization.

21530321716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168374 (or 168372 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 31.

The spelling of 21530321716 in words is "twenty-one billion, five hundred thirty million, three hundred twenty-one thousand, seven hundred sixteen".