21140001 has 8 divisors (see below), whose sum is σ = 31318560. Its totient is φ = 14093316.

The previous prime is 21139999. The next prime is 21140003. The reversal of 21140001 is 10004112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21139999) and next prime (21140003).

It is not a de Polignac number, because 21140001 - 2¹ = 21139999 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21140003) 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, 391455 + ... + 391508.

It is an arithmetic number, because the mean of its divisors is an integer number (3914820).

Almost surely, 2^21140001 is an apocalyptic number.

It is an amenable number.

21140001 is a deficient number, since it is larger than the sum of its proper divisors (10178559).

21140001 is an equidigital number, since it uses as much as digits as its factorization.

21140001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782972 (or 782966 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 21140001 is about 4597.8256817761. The cubic root of 21140001 is about 276.5041588515.

Adding to 21140001 its reverse (10004112), we get a palindrome (31144113).

The spelling of 21140001 in words is "twenty-one million, one hundred forty thousand, one".