20477207681 has 4 divisors (see below), whose sum is σ = 23402523072. Its totient is φ = 17551892292.

The previous prime is 20477207629. The next prime is 20477207689. The reversal of 20477207681 is 18670277402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20477207681 is a prime.

It is a super-2 number, since 2×20477207681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20477207689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1462657685 + ... + 1462657698.

It is an arithmetic number, because the mean of its divisors is an integer number (5850630768).

Almost surely, 2^20477207681 is an apocalyptic number.

It is an amenable number.

20477207681 is a deficient number, since it is larger than the sum of its proper divisors (2925315391).

20477207681 is an equidigital number, since it uses as much as digits as its factorization.

20477207681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2925315390.

The product of its (nonzero) digits is 263424, while the sum is 44.

The spelling of 20477207681 in words is "twenty billion, four hundred seventy-seven million, two hundred seven thousand, six hundred eighty-one".