21985163026 has 4 divisors (see below), whose sum is σ = 32977744542. Its totient is φ = 10992581512.

The previous prime is 21985163021. The next prime is 21985163047. The reversal of 21985163026 is 62036158912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18360521001 + 3624642025 = 135501^2 + 60205^2 .

It is not an unprimeable number, because it can be changed into a prime (21985163021) 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 as a sum of consecutive naturals, namely, 5496290755 + ... + 5496290758.

Almost surely, 2^21985163026 is an apocalyptic number.

21985163026 is a deficient number, since it is larger than the sum of its proper divisors (10992581516).

21985163026 is a wasteful number, since it uses less digits than its factorization.

21985163026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10992581515.

The product of its (nonzero) digits is 155520, while the sum is 43.

The spelling of 21985163026 in words is "twenty-one billion, nine hundred eighty-five million, one hundred sixty-three thousand, twenty-six".