21091763287 has 8 divisors (see below), whose sum is σ = 24617742336. Its totient is φ = 17694001752.

The previous prime is 21091763261. The next prime is 21091763293. The reversal of 21091763287 is 78236719012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21091763287 - 2⁷ = 21091763159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21091763227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32054023 + ... + 32054680.

It is an arithmetic number, because the mean of its divisors is an integer number (3077217792).

Almost surely, 2^21091763287 is an apocalyptic number.

21091763287 is a deficient number, since it is larger than the sum of its proper divisors (3525979049).

21091763287 is an equidigital number, since it uses as much as digits as its factorization.

21091763287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64108757.

The product of its (nonzero) digits is 254016, while the sum is 46.

It can be divided in two parts, 21091 and 763287, that added together give a triangular number (784378 = T₁₂₅₂).

The spelling of 21091763287 in words is "twenty-one billion, ninety-one million, seven hundred sixty-three thousand, two hundred eighty-seven".