212020640 has 72 divisors (see below), whose sum is σ = 542462508. Its totient is φ = 78274560.

The previous prime is 212020637. The next prime is 212020643. The reversal of 212020640 is 46020212.

It is an interprime number because it is at equal distance from previous prime (212020637) and next prime (212020643).

It can be written as a sum of positive squares in 6 ways, for example, as 12759184 + 199261456 = 3572^2 + 14116^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212020643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23120 + ... + 30960.

Almost surely, 2^212020640 is an apocalyptic number.

212020640 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 212020640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (271231254).

212020640 is an abundant number, since it is smaller than the sum of its proper divisors (330441868).

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

212020640 is a wasteful number, since it uses less digits than its factorization.

212020640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7882 (or 7861 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 212020640 is about 14560.9285418204. The cubic root of 212020640 is about 596.2925458992.

Adding to 212020640 its reverse (46020212), we get a palindrome (258040852).

The spelling of 212020640 in words is "two hundred twelve million, twenty thousand, six hundred forty".