221277420 has 480 divisors, whose sum is σ = 910694400. Its totient is φ = 43670016.

The previous prime is 221277383. The next prime is 221277421. The reversal of 221277420 is 24772122.

221277420 = T₁₉₁ + T₁₉₂ + ... + T₁₁₀₀.

221277420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221277421) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 2800941 + ... + 2801019.

It is an arithmetic number, because the mean of its divisors is an integer number (1897280).

Almost surely, 2^221277420 is an apocalyptic number.

221277420 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 221277420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (455347200).

221277420 is an abundant number, since it is smaller than the sum of its proper divisors (689416980).

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

221277420 is a wasteful number, since it uses less digits than its factorization.

221277420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 128 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 221277420 is about 14875.3964653047. The cubic root of 221277420 is about 604.8472350674.

The spelling of 221277420 in words is "two hundred twenty-one million, two hundred seventy-seven thousand, four hundred twenty".