20695987321 has 9 divisors (see below), whose sum is σ = 20813027781. Its totient is φ = 20579603772.

The previous prime is 20695987297. The next prime is 20695987343. The reversal of 20695987321 is 12378959602.

The square root of 20695987321 is 143861.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 20695987321 - 2¹¹ = 20695985273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20695987381) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 37835170 + ... + 37835716.

Almost surely, 2^20695987321 is an apocalyptic number.

20695987321 is the 143861-st square number.

20695987321 is the 71931-st centered octagonal number.

It is an amenable number.

20695987321 is a deficient number, since it is larger than the sum of its proper divisors (117040460).

20695987321 is an frugal number, since it uses more digits than its factorization.

20695987321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1620 (or 810 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 52.

It can be divided in two parts, 20695 and 987321, that added together give a square (1008016 = 1004²).

The spelling of 20695987321 in words is "twenty billion, six hundred ninety-five million, nine hundred eighty-seven thousand, three hundred twenty-one".