21341491 has 2 divisors, whose sum is σ = 21341492. Its totient is φ = 21341490.

The previous prime is 21341479. The next prime is 21341501. The reversal of 21341491 is 19414312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21341491 - 2⁷ = 21341363 is a prime.

It is equal to p_1350178 and since 21341491 and 1350178 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21341191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10670745 + 10670746.

It is an arithmetic number, because the mean of its divisors is an integer number (10670746).

Almost surely, 2^21341491 is an apocalyptic number.

21341491 is a deficient number, since it is larger than the sum of its proper divisors (1).

21341491 is an equidigital number, since it uses as much as digits as its factorization.

21341491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

The square root of 21341491 is about 4619.6851624326. The cubic root of 21341491 is about 277.3798565487.

The spelling of 21341491 in words is "twenty-one million, three hundred forty-one thousand, four hundred ninety-one".