211312031 has 4 divisors (see below), whose sum is σ = 241499472. Its totient is φ = 181124592.

The previous prime is 211311983. The next prime is 211312043. The reversal of 211312031 is 130213112.

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 211312031 - 2¹⁴ = 211295647 is a prime.

It is a super-2 number, since 2×211312031² = 89305548890689922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211311997 and 211312015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211312331) 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, 15093710 + ... + 15093723.

It is an arithmetic number, because the mean of its divisors is an integer number (60374868).

Almost surely, 2^211312031 is an apocalyptic number.

211312031 is a deficient number, since it is larger than the sum of its proper divisors (30187441).

211312031 is an equidigital number, since it uses as much as digits as its factorization.

211312031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30187440.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 211312031 is about 14536.5756283934. The cubic root of 211312031 is about 595.6275007850.

Adding to 211312031 its reverse (130213112), we get a palindrome (341525143).

The spelling of 211312031 in words is "two hundred eleven million, three hundred twelve thousand, thirty-one".