21113001 has 48 divisors (see below), whose sum is σ = 38766720. Its totient is φ = 11119680.

The previous prime is 21112999. The next prime is 21113017. The reversal of 21113001 is 10031112.

It is not a de Polignac number, because 21113001 - 2¹ = 21112999 is a prime.

It is a super-2 number, since 2×21113001² = 891517622452002, which contains 22 as substring.

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 (21113041) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31611 + ... + 32271.

It is an arithmetic number, because the mean of its divisors is an integer number (807640).

Almost surely, 2^21113001 is an apocalyptic number.

21113001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21113001 is a deficient number, since it is larger than the sum of its proper divisors (17653719).

21113001 is a wasteful number, since it uses less digits than its factorization.

21113001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 703 (or 684 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 9.

The square root of 21113001 is about 4594.8885731865. Note that the first 3 decimals coincide. The cubic root of 21113001 is about 276.3863917030.

Adding to 21113001 its reverse (10031112), we get a palindrome (31144113).

The spelling of 21113001 in words is "twenty-one million, one hundred thirteen thousand, one".