20806565734 has 4 divisors (see below), whose sum is σ = 31209848604. Its totient is φ = 10403282866.

The previous prime is 20806565723. The next prime is 20806565737. The reversal of 20806565734 is 43756560802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 43756560802 = 2 ⋅21878280401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20806565737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5201641432 + ... + 5201641435.

It is an arithmetic number, because the mean of its divisors is an integer number (7802462151).

Almost surely, 2^20806565734 is an apocalyptic number.

20806565734 is a deficient number, since it is larger than the sum of its proper divisors (10403282870).

20806565734 is a wasteful number, since it uses less digits than its factorization.

20806565734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10403282869.

The product of its (nonzero) digits is 1209600, while the sum is 46.

The spelling of 20806565734 in words is "twenty billion, eight hundred six million, five hundred sixty-five thousand, seven hundred thirty-four".