215648784400 has 405 divisors, whose sum is σ = 628626384477. Its totient is φ = 70882963200.

The previous prime is 215648784397. The next prime is 215648784419. The reversal of 215648784400 is 4487846512.

It is a happy number.

The square root of 215648784400 is 464380.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 77633562384 + 138015222016 = 278628^2 + 371504^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 2015409147 + ... + 2015409253.

Almost surely, 2^215648784400 is an apocalyptic number.

215648784400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

215648784400 is the 464380-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215648784400

215648784400 is an abundant number, since it is smaller than the sum of its proper divisors (412977600077).

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

215648784400 is a wasteful number, since it uses less digits than its factorization.

215648784400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 1720320, while the sum is 49.

Multiplying 215648784400 by its sum of digits (49), we get a square (10566790435600 = 3250660²).

215648784400 divided by its sum of digits (49) gives a square (4400995600 = 66340²).

The spelling of 215648784400 in words is "two hundred fifteen billion, six hundred forty-eight million, seven hundred eighty-four thousand, four hundred".