212109520 has 80 divisors (see below), whose sum is σ = 565463808. Its totient is φ = 72483840.

The previous prime is 212109503. The next prime is 212109529. The reversal of 212109520 is 25901212.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-4 number, since 4×212109520⁴ (a number of 34 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 212109491 and 212109500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212109529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 291397 + ... + 292123.

Almost surely, 2^212109520 is an apocalyptic number.

212109520 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 212109520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282731904).

212109520 is an abundant number, since it is smaller than the sum of its proper divisors (353354288).

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

212109520 is a wasteful number, since it uses less digits than its factorization.

212109520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1268 (or 1262 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 212109520 is about 14563.9802251994. The cubic root of 212109520 is about 596.3758570923.

The spelling of 212109520 in words is "two hundred twelve million, one hundred nine thousand, five hundred twenty".