21450263 has 4 divisors (see below), whose sum is σ = 21507240. Its totient is φ = 21393288.

The previous prime is 21450241. The next prime is 21450293. The reversal of 21450263 is 36205412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21450263 is a prime.

It is a super-2 number, since 2×21450263² = 920227565538338, 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 (21450293) 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, 27920 + ... + 28677.

It is an arithmetic number, because the mean of its divisors is an integer number (5376810).

Almost surely, 2^21450263 is an apocalyptic number.

21450263 is a deficient number, since it is larger than the sum of its proper divisors (56977).

21450263 is an equidigital number, since it uses as much as digits as its factorization.

21450263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56976.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21450263 is about 4631.4428637305. The cubic root of 21450263 is about 277.8503024082.

Adding to 21450263 its reverse (36205412), we get a palindrome (57655675).

It can be divided in two parts, 2145026 and 3, that multiplied together give a triangular number (6435078 = T₃₅₈₇).

The spelling of 21450263 in words is "twenty-one million, four hundred fifty thousand, two hundred sixty-three".