21372401 has 8 divisors (see below), whose sum is σ = 21624000. Its totient is φ = 21122640.

The previous prime is 21372367. The next prime is 21372413. The reversal of 21372401 is 10427312.

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 21372401 - 2¹⁰ = 21371377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21372431) 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 7 ways as a sum of consecutive naturals, for example, 41735 + ... + 42243.

It is an arithmetic number, because the mean of its divisors is an integer number (2703000).

Almost surely, 2^21372401 is an apocalyptic number.

It is an amenable number.

21372401 is a deficient number, since it is larger than the sum of its proper divisors (251599).

21372401 is a wasteful number, since it uses less digits than its factorization.

21372401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 919.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21372401 is about 4623.0294180332. The cubic root of 21372401 is about 277.5137065437.

Adding to 21372401 its reverse (10427312), we get a palindrome (31799713).

The spelling of 21372401 in words is "twenty-one million, three hundred seventy-two thousand, four hundred one".