21975039 has 12 divisors (see below), whose sum is σ = 33412600. Its totient is φ = 13878864.

The previous prime is 21975013. The next prime is 21975047. The reversal of 21975039 is 93057912.

It is not a de Polignac number, because 21975039 - 2¹² = 21970943 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21974994 and 21975012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21975049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64084 + ... + 64425.

Almost surely, 2^21975039 is an apocalyptic number.

21975039 is a deficient number, since it is larger than the sum of its proper divisors (11437561).

21975039 is a wasteful number, since it uses less digits than its factorization.

21975039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128534 (or 128531 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 36.

The square root of 21975039 is about 4687.7541531100. The cubic root of 21975039 is about 280.0979206835.

The spelling of 21975039 in words is "twenty-one million, nine hundred seventy-five thousand, thirty-nine".