212820397440 has 128 divisors (see below), whose sum is σ = 775274353920. Its totient is φ = 48644659200.

The previous prime is 212820397429. The next prime is 212820397463. The reversal of 212820397440 is 44793028212.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 212820397392 and 212820397401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7903986 + ... + 7930865.

It is an arithmetic number, because the mean of its divisors is an integer number (6056830890).

Almost surely, 2^212820397440 is an apocalyptic number.

212820397440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212820397440 is an abundant number, since it is smaller than the sum of its proper divisors (562453956480).

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

212820397440 is a wasteful number, since it uses less digits than its factorization.

212820397440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15834880 (or 15834868 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 42.

The spelling of 212820397440 in words is "two hundred twelve billion, eight hundred twenty million, three hundred ninety-seven thousand, four hundred forty".