21113031 has 8 divisors (see below), whose sum is σ = 29806704. Its totient is φ = 13247360.

The previous prime is 21113023. The next prime is 21113041. The reversal of 21113031 is 13031112.

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 21113031 - 2³ = 21113023 is a prime.

It is a super-2 number, since 2×21113031² = 891520156013922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21112998 and 21113016.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 206940 + ... + 207041.

It is an arithmetic number, because the mean of its divisors is an integer number (3725838).

Almost surely, 2^21113031 is an apocalyptic number.

21113031 is a deficient number, since it is larger than the sum of its proper divisors (8693673).

21113031 is a wasteful number, since it uses less digits than its factorization.

21113031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414001.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 21113031 is about 4594.8918376824. The cubic root of 21113031 is about 276.3865226111.

Adding to 21113031 its reverse (13031112), we get a palindrome (34144143).

The spelling of 21113031 in words is "twenty-one million, one hundred thirteen thousand, thirty-one".