21198843587 has 2 divisors, whose sum is σ = 21198843588. Its totient is φ = 21198843586.

The previous prime is 21198843581. The next prime is 21198843637. The reversal of 21198843587 is 78534889112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21198843587 - 2³² = 16903876291 is a prime.

It is not a weakly prime, because it can be changed into another prime (21198843581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10599421793 + 10599421794.

It is an arithmetic number, because the mean of its divisors is an integer number (10599421794).

Almost surely, 2^21198843587 is an apocalyptic number.

21198843587 is a deficient number, since it is larger than the sum of its proper divisors (1).

21198843587 is an equidigital number, since it uses as much as digits as its factorization.

21198843587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3870720, while the sum is 56.

The spelling of 21198843587 in words is "twenty-one billion, one hundred ninety-eight million, eight hundred forty-three thousand, five hundred eighty-seven".