21340553 has 8 divisors (see below), whose sum is σ = 24192000. Its totient is φ = 18661968.

The previous prime is 21340547. The next prime is 21340567. The reversal of 21340553 is 35504312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21340553 - 2⁴ = 21340537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21340523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42953 + ... + 43446.

It is an arithmetic number, because the mean of its divisors is an integer number (3024000).

Almost surely, 2^21340553 is an apocalyptic number.

It is an amenable number.

21340553 is a deficient number, since it is larger than the sum of its proper divisors (2851447).

21340553 is a wasteful number, since it uses less digits than its factorization.

21340553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86431.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 21340553 is about 4619.5836392472. The cubic root of 21340553 is about 277.3757926946.

Adding to 21340553 its reverse (35504312), we get a palindrome (56844865).

The spelling of 21340553 in words is "twenty-one million, three hundred forty thousand, five hundred fifty-three".