21200987 has 2 divisors, whose sum is σ = 21200988. Its totient is φ = 21200986.

The previous prime is 21200983. The next prime is 21201031. The reversal of 21200987 is 78900212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21200987 - 2² = 21200983 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21200983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600493 + 10600494.

It is an arithmetic number, because the mean of its divisors is an integer number (10600494).

Almost surely, 2^21200987 is an apocalyptic number.

21200987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200987 is an equidigital number, since it uses as much as digits as its factorization.

21200987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 21200987 is about 4604.4529533920. The cubic root of 21200987 is about 276.7697957495.

The spelling of 21200987 in words is "twenty-one million, two hundred thousand, nine hundred eighty-seven".