21893747 has 2 divisors, whose sum is σ = 21893748. Its totient is φ = 21893746.

The previous prime is 21893699. The next prime is 21893749. The reversal of 21893747 is 74739812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21893747 - 2¹⁰ = 21892723 is a prime.

Together with 21893749, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21893749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10946873 + 10946874.

It is an arithmetic number, because the mean of its divisors is an integer number (10946874).

Almost surely, 2^21893747 is an apocalyptic number.

21893747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21893747 is an equidigital number, since it uses as much as digits as its factorization.

21893747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 41.

The square root of 21893747 is about 4679.0754428626. The cubic root of 21893747 is about 279.7521062761.

The spelling of 21893747 in words is "twenty-one million, eight hundred ninety-three thousand, seven hundred forty-seven".