21152001 has 16 divisors (see below), whose sum is σ = 31080896. Its totient is φ = 12712896.

The previous prime is 21151981. The next prime is 21152003. The reversal of 21152001 is 10025112.

It is not a de Polignac number, because 21152001 - 2⁶ = 21151937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21152003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4630 + ... + 7983.

It is an arithmetic number, because the mean of its divisors is an integer number (1942556).

Almost surely, 2^21152001 is an apocalyptic number.

It is an amenable number.

21152001 is a deficient number, since it is larger than the sum of its proper divisors (9928895).

21152001 is a wasteful number, since it uses less digits than its factorization.

21152001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12672.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21152001 is about 4599.1304612937. The cubic root of 21152001 is about 276.5564676203.

Adding to 21152001 its reverse (10025112), we get a palindrome (31177113).

The spelling of 21152001 in words is "twenty-one million, one hundred fifty-two thousand, one".