21437963 has 2 divisors, whose sum is σ = 21437964. Its totient is φ = 21437962.

The previous prime is 21437939. The next prime is 21438013. The reversal of 21437963 is 36973412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21437963 - 2¹⁰ = 21436939 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21437063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10718981 + 10718982.

It is an arithmetic number, because the mean of its divisors is an integer number (10718982).

Almost surely, 2^21437963 is an apocalyptic number.

21437963 is a deficient number, since it is larger than the sum of its proper divisors (1).

21437963 is an equidigital number, since it uses as much as digits as its factorization.

21437963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 35.

The square root of 21437963 is about 4630.1147933934. The cubic root of 21437963 is about 277.7971839894.

The spelling of 21437963 in words is "twenty-one million, four hundred thirty-seven thousand, nine hundred sixty-three".