21295493 has 4 divisors (see below), whose sum is σ = 22221408. Its totient is φ = 20369580.

The previous prime is 21295489. The next prime is 21295507. The reversal of 21295493 is 39459212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21295493 - 2² = 21295489 is a prime.

It is a super-2 number, since 2×21295493² = 906996044226098, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21298493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 462923 + ... + 462968.

It is an arithmetic number, because the mean of its divisors is an integer number (5555352).

Almost surely, 2^21295493 is an apocalyptic number.

21295493 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21295493 is a deficient number, since it is larger than the sum of its proper divisors (925915).

21295493 is an equidigital number, since it uses as much as digits as its factorization.

21295493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925914.

The product of its digits is 19440, while the sum is 35.

The square root of 21295493 is about 4614.7039991748. The cubic root of 21295493 is about 277.1804313039.

The spelling of 21295493 in words is "twenty-one million, two hundred ninety-five thousand, four hundred ninety-three".