211628991 has 24 divisors (see below), whose sum is σ = 329844864. Its totient is φ = 120340080.

The previous prime is 211628983. The next prime is 211629017. The reversal of 211628991 is 199826112.

It is not a de Polignac number, because 211628991 - 2³ = 211628983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211628941) 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, 27606 + ... + 34428.

It is an arithmetic number, because the mean of its divisors is an integer number (13743536).

Almost surely, 2^211628991 is an apocalyptic number.

211628991 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

211628991 is a deficient number, since it is larger than the sum of its proper divisors (118215873).

211628991 is a wasteful number, since it uses less digits than its factorization.

211628991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7051 (or 7044 counting only the distinct ones).

The product of its digits is 15552, while the sum is 39.

The square root of 211628991 is about 14547.4736982062. The cubic root of 211628991 is about 595.9251581998.

The spelling of 211628991 in words is "two hundred eleven million, six hundred twenty-eight thousand, nine hundred ninety-one".