21215771114987 has 2 divisors, whose sum is σ = 21215771114988. Its totient is φ = 21215771114986.

The previous prime is 21215771114977. The next prime is 21215771115031. The reversal of 21215771114987 is 78941117751212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21215771114987 - 2²⁸ = 21215502679531 is a prime.

It is not a weakly prime, because it can be changed into another prime (21215771114927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10607885557493 + 10607885557494.

It is an arithmetic number, because the mean of its divisors is an integer number (10607885557494).

Almost surely, 2^{21215771114987} is an apocalyptic number.

21215771114987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21215771114987 is an equidigital number, since it uses as much as digits as its factorization.

21215771114987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1975680, while the sum is 56.

The spelling of 21215771114987 in words is "twenty-one trillion, two hundred fifteen billion, seven hundred seventy-one million, one hundred fourteen thousand, nine hundred eighty-seven".