21481403 has 2 divisors, whose sum is σ = 21481404. Its totient is φ = 21481402.

The previous prime is 21481399. The next prime is 21481409. The reversal of 21481403 is 30418412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21481403 - 2² = 21481399 is a prime.

It is a super-2 number, since 2×21481403² = 922901349696818, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21481409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10740701 + 10740702.

It is an arithmetic number, because the mean of its divisors is an integer number (10740702).

Almost surely, 2^21481403 is an apocalyptic number.

21481403 is a deficient number, since it is larger than the sum of its proper divisors (1).

21481403 is an equidigital number, since it uses as much as digits as its factorization.

21481403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 21481403 is about 4634.8034478282. The cubic root of 21481403 is about 277.9846919784.

Adding to 21481403 its reverse (30418412), we get a palindrome (51899815).

The spelling of 21481403 in words is "twenty-one million, four hundred eighty-one thousand, four hundred three".