21201002987 has 2 divisors, whose sum is σ = 21201002988. Its totient is φ = 21201002986.

The previous prime is 21201002941. The next prime is 21201003023. The reversal of 21201002987 is 78920010212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21201002987 - 2²⁰ = 21199954411 is a prime.

It is not a weakly prime, because it can be changed into another prime (21201002087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600501493 + 10600501494.

It is an arithmetic number, because the mean of its divisors is an integer number (10600501494).

Almost surely, 2^21201002987 is an apocalyptic number.

21201002987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201002987 is an equidigital number, since it uses as much as digits as its factorization.

21201002987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 32.

The spelling of 21201002987 in words is "twenty-one billion, two hundred one million, two thousand, nine hundred eighty-seven".