21343788 has 36 divisors (see below), whose sum is σ = 54763800. Its totient is φ = 7007616.

The previous prime is 21343787. The next prime is 21343801. The reversal of 21343788 is 88734312.

21343788 is a `hidden beast` number, since 213 + 437 + 8 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21343787) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2013 + ... + 6836.

Almost surely, 2^21343788 is an apocalyptic number.

It is an amenable number.

21343788 is an abundant number, since it is smaller than the sum of its proper divisors (33420012).

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

21343788 is a wasteful number, since it uses less digits than its factorization.

21343788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8926 (or 8921 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 21343788 is about 4619.9337657590. The cubic root of 21343788 is about 277.3898077227.

The spelling of 21343788 in words is "twenty-one million, three hundred forty-three thousand, seven hundred eighty-eight".