21439267618987 has 2 divisors, whose sum is σ = 21439267618988. Its totient is φ = 21439267618986.

The previous prime is 21439267618907. The next prime is 21439267619017. The reversal of 21439267618987 is 78981676293412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21439267618987 - 2¹¹ = 21439267616939 is a prime.

It is not a weakly prime, because it can be changed into another prime (21439267618907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10719633809493 + 10719633809494.

It is an arithmetic number, because the mean of its divisors is an integer number (10719633809494).

Almost surely, 2^{21439267618987} is an apocalyptic number.

21439267618987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21439267618987 is an equidigital number, since it uses as much as digits as its factorization.

21439267618987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 438939648, while the sum is 73.

The spelling of 21439267618987 in words is "twenty-one trillion, four hundred thirty-nine billion, two hundred sixty-seven million, six hundred eighteen thousand, nine hundred eighty-seven".