211491645 has 24 divisors (see below), whose sum is σ = 359469984. Its totient is φ = 106158336.

The previous prime is 211491629. The next prime is 211491649. The reversal of 211491645 is 546194112.

It is not a de Polignac number, because 211491645 - 2⁴ = 211491629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211491649) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20059 + ... + 28728.

It is an arithmetic number, because the mean of its divisors is an integer number (14977916).

Almost surely, 2^211491645 is an apocalyptic number.

It is an amenable number.

211491645 is a deficient number, since it is larger than the sum of its proper divisors (147978339).

211491645 is a wasteful number, since it uses less digits than its factorization.

211491645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48829 (or 48812 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 211491645 is about 14542.7523185950. The cubic root of 211491645 is about 595.7962129656.

The spelling of 211491645 in words is "two hundred eleven million, four hundred ninety-one thousand, six hundred forty-five".