211491840 has 264 divisors, whose sum is σ = 789683472. Its totient is φ = 48168960.

The previous prime is 211491829. The next prime is 211491853. The reversal of 211491840 is 48194112.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 211491798 and 211491807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 752500 + ... + 752780.

Almost surely, 2^211491840 is an apocalyptic number.

211491840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211491840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394841736).

211491840 is an abundant number, since it is smaller than the sum of its proper divisors (578191632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211491840 is a wasteful number, since it uses less digits than its factorization.

211491840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 298 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 211491840 is about 14542.7590229640. The cubic root of 211491840 is about 595.7963960780.

The spelling of 211491840 in words is "two hundred eleven million, four hundred ninety-one thousand, eight hundred forty".