21481402 has 16 divisors (see below), whose sum is σ = 34784640. Its totient is φ = 9918832.

The previous prime is 21481399. The next prime is 21481403. The reversal of 21481402 is 20418412.

It is a super-2 number, since 2×21481402² = 922901263771208, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21481403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6718 + ... + 9385.

It is an arithmetic number, because the mean of its divisors is an integer number (2174040).

Almost surely, 2^21481402 is an apocalyptic number.

21481402 is a deficient number, since it is larger than the sum of its proper divisors (13303238).

21481402 is a wasteful number, since it uses less digits than its factorization.

21481402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16157.

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 21481402 is about 4634.8033399487. The cubic root of 21481402 is about 277.9846876648.

Adding to 21481402 its reverse (20418412), we get a palindrome (41899814).

The spelling of 21481402 in words is "twenty-one million, four hundred eighty-one thousand, four hundred two".