21340475 has 18 divisors (see below), whose sum is σ = 28659996. Its totient is φ = 15756000.

The previous prime is 21340471. The next prime is 21340489. The reversal of 21340475 is 57404312.

It is not a de Polignac number, because 21340475 - 2² = 21340471 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21340471) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1700 + ... + 6750.

It is an arithmetic number, because the mean of its divisors is an integer number (1592222).

Almost surely, 2^21340475 is an apocalyptic number.

21340475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21340475 is a deficient number, since it is larger than the sum of its proper divisors (7319521).

21340475 is a wasteful number, since it uses less digits than its factorization.

21340475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5087 (or 5069 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 21340475 is about 4619.5751969202. The cubic root of 21340475 is about 277.3754547568.

Adding to 21340475 its reverse (57404312), we get a palindrome (78744787).

The spelling of 21340475 in words is "twenty-one million, three hundred forty thousand, four hundred seventy-five".