21700975 has 6 divisors (see below), whose sum is σ = 26909240. Its totient is φ = 17360760.

The previous prime is 21700969. The next prime is 21700979. The reversal of 21700975 is 57900712.

It is not a de Polignac number, because 21700975 - 2¹¹ = 21698927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21700979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 433995 + ... + 434044.

Almost surely, 2^21700975 is an apocalyptic number.

21700975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21700975 is a deficient number, since it is larger than the sum of its proper divisors (5208265).

21700975 is an equidigital number, since it uses as much as digits as its factorization.

21700975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868049 (or 868044 counting only the distinct ones).

The product of its (nonzero) digits is 4410, while the sum is 31.

The square root of 21700975 is about 4658.4305296956. The cubic root of 21700975 is about 278.9286226028.

The spelling of 21700975 in words is "twenty-one million, seven hundred thousand, nine hundred seventy-five".