21782610887 has 2 divisors, whose sum is σ = 21782610888. Its totient is φ = 21782610886.

The previous prime is 21782610869. The next prime is 21782610907. The reversal of 21782610887 is 78801628712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21782610887 - 2⁶ = 21782610823 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21782610827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10891305443 + 10891305444.

It is an arithmetic number, because the mean of its divisors is an integer number (10891305444).

Almost surely, 2^21782610887 is an apocalyptic number.

21782610887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21782610887 is an equidigital number, since it uses as much as digits as its factorization.

21782610887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 602112, while the sum is 50.

The spelling of 21782610887 in words is "twenty-one billion, seven hundred eighty-two million, six hundred ten thousand, eight hundred eighty-seven".