20021769891 has 32 divisors (see below), whose sum is σ = 30538368000. Its totient is φ = 12956708160.

The previous prime is 20021769881. The next prime is 20021769991. The reversal of 20021769891 is 19896712002.

It is not a de Polignac number, because 20021769891 - 2¹³ = 20021761699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20021769811) 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 31 ways as a sum of consecutive naturals, for example, 174850 + ... + 265736.

It is an arithmetic number, because the mean of its divisors is an integer number (954324000).

Almost surely, 2^20021769891 is an apocalyptic number.

20021769891 is a deficient number, since it is larger than the sum of its proper divisors (10516598109).

20021769891 is a wasteful number, since it uses less digits than its factorization.

20021769891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91136 (or 91130 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The spelling of 20021769891 in words is "twenty billion, twenty-one million, seven hundred sixty-nine thousand, eight hundred ninety-one".