21357324 has 24 divisors (see below), whose sum is σ = 55371120. Its totient is φ = 7119072.

The previous prime is 21357313. The next prime is 21357331. The reversal of 21357324 is 42375312.

It is a super-2 number, since 2×21357324² = 912270576881952, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 98769 + ... + 98984.

It is an arithmetic number, because the mean of its divisors is an integer number (2307130).

Almost surely, 2^21357324 is an apocalyptic number.

It is an amenable number.

21357324 is an abundant number, since it is smaller than the sum of its proper divisors (34013796).

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

21357324 is a wasteful number, since it uses less digits than its factorization.

21357324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197766 (or 197758 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 21357324 is about 4621.3984896349. The cubic root of 21357324 is about 277.4484345384.

The spelling of 21357324 in words is "twenty-one million, three hundred fifty-seven thousand, three hundred twenty-four".