21321402 has 16 divisors (see below), whose sum is σ = 43227840. Its totient is φ = 7009632.

The previous prime is 21321379. The next prime is 21321407. The reversal of 21321402 is 20412312.

It is not an unprimeable number, because it can be changed into a prime (21321407) 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 7 ways as a sum of consecutive naturals, for example, 23902 + ... + 24777.

It is an arithmetic number, because the mean of its divisors is an integer number (2701740).

Almost surely, 2^21321402 is an apocalyptic number.

21321402 is an abundant number, since it is smaller than the sum of its proper divisors (21906438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21321402 is a wasteful number, since it uses less digits than its factorization.

21321402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48757.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21321402 is about 4617.5103681530. The cubic root of 21321402 is about 277.2927955701.

Adding to 21321402 its reverse (20412312), we get a palindrome (41733714).

The spelling of 21321402 in words is "twenty-one million, three hundred twenty-one thousand, four hundred two".