20402723645 has 16 divisors (see below), whose sum is σ = 24828075072. Its totient is φ = 16092478080.

The previous prime is 20402723603. The next prime is 20402723657. The reversal of 20402723645 is 54632720402.

It is not a de Polignac number, because 20402723645 - 2²⁰ = 20401675069 is a prime.

It is a super-2 number, since 2×20402723645² (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 15 ways as a sum of consecutive naturals, for example, 1116230 + ... + 1134360.

It is an arithmetic number, because the mean of its divisors is an integer number (1551754692).

Almost surely, 2^20402723645 is an apocalyptic number.

It is an amenable number.

20402723645 is a deficient number, since it is larger than the sum of its proper divisors (4425351427).

20402723645 is a wasteful number, since it uses less digits than its factorization.

20402723645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21292.

The product of its (nonzero) digits is 80640, while the sum is 35.

The spelling of 20402723645 in words is "twenty billion, four hundred two million, seven hundred twenty-three thousand, six hundred forty-five".