211221010 has 64 divisors (see below), whose sum is σ = 510499584. Its totient is φ = 60768000.

The previous prime is 211220993. The next prime is 211221013. The reversal of 211221010 is 10122112.

211221010 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×211221010² = 89228630130840200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (211221013) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 541 + ... + 20560.

It is an arithmetic number, because the mean of its divisors is an integer number (7976556).

Almost surely, 2^211221010 is an apocalyptic number.

211221010 is an abundant number, since it is smaller than the sum of its proper divisors (299278574).

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

211221010 is a wasteful number, since it uses less digits than its factorization.

211221010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21139.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 211221010 is about 14533.4445332137. Note that the first 3 decimals coincide. The cubic root of 211221010 is about 595.5419678782.

Adding to 211221010 its reverse (10122112), we get a palindrome (221343122).

The spelling of 211221010 in words is "two hundred eleven million, two hundred twenty-one thousand, ten".