21575051 has 8 divisors (see below), whose sum is σ = 22866000. Its totient is φ = 20299680.

The previous prime is 21575041. The next prime is 21575053. The reversal of 21575051 is 15057512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21575051 - 2¹⁰ = 21574027 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21575051.

It is not an unprimeable number, because it can be changed into a prime (21575053) 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, 980 + ... + 6641.

It is an arithmetic number, because the mean of its divisors is an integer number (2858250).

Almost surely, 2^21575051 is an apocalyptic number.

21575051 is a deficient number, since it is larger than the sum of its proper divisors (1290949).

21575051 is a wasteful number, since it uses less digits than its factorization.

21575051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7789.

The product of its (nonzero) digits is 1750, while the sum is 26.

The square root of 21575051 is about 4644.8951548985. The cubic root of 21575051 is about 278.3880637072.

The spelling of 21575051 in words is "twenty-one million, five hundred seventy-five thousand, fifty-one".