20890542066 has 24 divisors (see below), whose sum is σ = 43983337680. Its totient is φ = 6596525952.

The previous prime is 20890542059. The next prime is 20890542119. The reversal of 20890542066 is 66024509802.

It is a super-2 number, since 2×20890542066² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1536450 + ... + 1549986.

It is an arithmetic number, because the mean of its divisors is an integer number (1832639070).

Almost surely, 2^20890542066 is an apocalyptic number.

20890542066 is an abundant number, since it is smaller than the sum of its proper divisors (23092795614).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20890542066 is an frugal number, since it uses more digits than its factorization.

20890542066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27098 (or 13561 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The spelling of 20890542066 in words is "twenty billion, eight hundred ninety million, five hundred forty-two thousand, sixty-six".