20420537761 has 16 divisors (see below), whose sum is σ = 22653892800. Its totient is φ = 18287720640.

The previous prime is 20420537719. The next prime is 20420537771. The reversal of 20420537761 is 16773502402.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20420537761 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20420537761.

It is not an unprimeable number, because it can be changed into a prime (20420537771) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39295 + ... + 205876.

It is an arithmetic number, because the mean of its divisors is an integer number (1415868300).

Almost surely, 2^20420537761 is an apocalyptic number.

It is an amenable number.

20420537761 is a deficient number, since it is larger than the sum of its proper divisors (2233355039).

20420537761 is a wasteful number, since it uses less digits than its factorization.

20420537761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245376.

The product of its (nonzero) digits is 70560, while the sum is 37.

The spelling of 20420537761 in words is "twenty billion, four hundred twenty million, five hundred thirty-seven thousand, seven hundred sixty-one".