221772400 has 30 divisors (see below), whose sum is σ = 532809152. Its totient is φ = 88708800.

The previous prime is 221772379. The next prime is 221772409. The reversal of 221772400 is 4277122.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221772409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 276816 + ... + 277615.

Almost surely, 2^221772400 is an apocalyptic number.

221772400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221772400 is an abundant number, since it is smaller than the sum of its proper divisors (311036752).

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

221772400 is a wasteful number, since it uses less digits than its factorization.

221772400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554449 (or 554438 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 25.

The square root of 221772400 is about 14892.0247112339. The cubic root of 221772400 is about 605.2978975981.

The spelling of 221772400 in words is "two hundred twenty-one million, seven hundred seventy-two thousand, four hundred".