21342400 has 42 divisors (see below), whose sum is σ = 52519580. Its totient is φ = 8536320.

The previous prime is 21342383. The next prime is 21342407. The reversal of 21342400 is 424312.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (21342407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5070 + ... + 8269.

Almost surely, 2^21342400 is an apocalyptic number.

21342400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21342400 is an abundant number, since it is smaller than the sum of its proper divisors (31177180).

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

21342400 is a wasteful number, since it uses less digits than its factorization.

21342400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13361 (or 13346 counting only the distinct ones).

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

The square root of 21342400 is about 4619.7835447129. The cubic root of 21342400 is about 277.3837946476.

Adding to 21342400 its reverse (424312), we get a palindrome (21766712).

It can be divided in two parts, 2134 and 2400, that multiplied together give a triangular number (5121600 = T₃₂₀₀).

The spelling of 21342400 in words is "twenty-one million, three hundred forty-two thousand, four hundred".