21400342 has 8 divisors (see below), whose sum is σ = 32121432. Its totient is φ = 10693200.

The previous prime is 21400277. The next prime is 21400343. The reversal of 21400342 is 24300412.

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 (21400343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2217 + ... + 6907.

It is an arithmetic number, because the mean of its divisors is an integer number (4015179).

Almost surely, 2^21400342 is an apocalyptic number.

21400342 is a deficient number, since it is larger than the sum of its proper divisors (10721090).

21400342 is a wasteful number, since it uses less digits than its factorization.

21400342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6974.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21400342 is about 4626.0503672139. The cubic root of 21400342 is about 277.6345888268.

Adding to 21400342 its reverse (24300412), we get a palindrome (45700754).

The spelling of 21400342 in words is "twenty-one million, four hundred thousand, three hundred forty-two".