21401603 has 4 divisors (see below), whose sum is σ = 21430488. Its totient is φ = 21372720.

The previous prime is 21401593. The next prime is 21401617. The reversal of 21401603 is 30610412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21401603 - 2⁶ = 21401539 is a prime.

It is a super-2 number, since 2×21401603² = 916057221939218, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21401663) 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, 13301 + ... + 14822.

It is an arithmetic number, because the mean of its divisors is an integer number (5357622).

Almost surely, 2^21401603 is an apocalyptic number.

21401603 is a deficient number, since it is larger than the sum of its proper divisors (28885).

21401603 is an equidigital number, since it uses as much as digits as its factorization.

21401603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28884.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21401603 is about 4626.1866585775. The cubic root of 21401603 is about 277.6400418602.

The spelling of 21401603 in words is "twenty-one million, four hundred one thousand, six hundred three".