20565851965 has 8 divisors (see below), whose sum is σ = 24766229088. Its totient is φ = 16394543760.

The previous prime is 20565851941. The next prime is 20565851989. The reversal of 20565851965 is 56915856502.

It is an interprime number because it is at equal distance from previous prime (20565851941) and next prime (20565851989).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20565851965 - 2¹³ = 20565843773 is a prime.

It is a super-2 number, since 2×20565851965² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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, 7265671 + ... + 7268500.

It is an arithmetic number, because the mean of its divisors is an integer number (3095778636).

Almost surely, 2^20565851965 is an apocalyptic number.

It is an amenable number.

20565851965 is a deficient number, since it is larger than the sum of its proper divisors (4200377123).

20565851965 is a wasteful number, since it uses less digits than its factorization.

20565851965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14534459.

The product of its (nonzero) digits is 3240000, while the sum is 52.

The spelling of 20565851965 in words is "twenty billion, five hundred sixty-five million, eight hundred fifty-one thousand, nine hundred sixty-five".