21452390 has 8 divisors (see below), whose sum is σ = 38614320. Its totient is φ = 8580952.

The previous prime is 21452363. The next prime is 21452393. The reversal of 21452390 is 9325412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21452393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1072610 + ... + 1072629.

It is an arithmetic number, because the mean of its divisors is an integer number (4826790).

Almost surely, 2^21452390 is an apocalyptic number.

21452390 is a deficient number, since it is larger than the sum of its proper divisors (17161930).

21452390 is a wasteful number, since it uses less digits than its factorization.

21452390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2145246.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21452390 is about 4631.6724841033. The cubic root of 21452390 is about 277.8594859484.

The spelling of 21452390 in words is "twenty-one million, four hundred fifty-two thousand, three hundred ninety".