21173011 has 12 divisors (see below), whose sum is σ = 22631400. Its totient is φ = 19803168.

The previous prime is 21172999. The next prime is 21173021. The reversal of 21173011 is 11037112.

It is not a de Polignac number, because 21173011 - 2⁵ = 21172979 is a prime.

It is a super-2 number, since 2×21173011² = 896592789612242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21173021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31800 + ... + 32458.

It is an arithmetic number, because the mean of its divisors is an integer number (1885950).

Almost surely, 2^21173011 is an apocalyptic number.

21173011 is a deficient number, since it is larger than the sum of its proper divisors (1458389).

21173011 is an equidigital number, since it uses as much as digits as its factorization.

21173011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786 (or 767 counting only the distinct ones).

The product of its (nonzero) digits is 42, while the sum is 16.

The square root of 21173011 is about 4601.4140217981. The cubic root of 21173011 is about 276.6480039346.

The spelling of 21173011 in words is "twenty-one million, one hundred seventy-three thousand, eleven".