20766277421 has 4 divisors (see below), whose sum is σ = 21669159072. Its totient is φ = 19863395772.

The previous prime is 20766277391. The next prime is 20766277429. The reversal of 20766277421 is 12477266702.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12477266702 = 2 ⋅6238633351.

It is a cyclic number.

It is not a de Polignac number, because 20766277421 - 2³⁴ = 3586408237 is a prime.

It is a super-2 number, since 2×20766277421² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20766277429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 451440791 + ... + 451440836.

It is an arithmetic number, because the mean of its divisors is an integer number (5417289768).

Almost surely, 2^20766277421 is an apocalyptic number.

It is an amenable number.

20766277421 is a deficient number, since it is larger than the sum of its proper divisors (902881651).

20766277421 is an equidigital number, since it uses as much as digits as its factorization.

20766277421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902881650.

The product of its (nonzero) digits is 395136, while the sum is 44.

The spelling of 20766277421 in words is "twenty billion, seven hundred sixty-six million, two hundred seventy-seven thousand, four hundred twenty-one".