21825001 has 4 divisors (see below), whose sum is σ = 23809104. Its totient is φ = 19840900.

The previous prime is 21824987. The next prime is 21825017. The reversal of 21825001 is 10052812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21825001 - 2⁵ = 21824969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21825001.

It is not an unprimeable number, because it can be changed into a prime (21825031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 992035 + ... + 992056.

It is an arithmetic number, because the mean of its divisors is an integer number (5952276).

Almost surely, 2^21825001 is an apocalyptic number.

It is an amenable number.

21825001 is a deficient number, since it is larger than the sum of its proper divisors (1984103).

21825001 is a wasteful number, since it uses less digits than its factorization.

21825001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1984102.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 21825001 is about 4671.7235577461. The cubic root of 21825001 is about 279.4589936246.

Adding to 21825001 its reverse (10052812), we get a palindrome (31877813).

The spelling of 21825001 in words is "twenty-one million, eight hundred twenty-five thousand, one".