221401025 has 24 divisors (see below), whose sum is σ = 285924408. Its totient is φ = 169920000.

The previous prime is 221401009. The next prime is 221401049. The reversal of 221401025 is 520104122.

221401025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 12 ways, for example, as 186022321 + 35378704 = 13639^2 + 5948^2 .

It is not a de Polignac number, because 221401025 - 2⁴ = 221401009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221400994 and 221401012.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60755 + ... + 64295.

It is an arithmetic number, because the mean of its divisors is an integer number (11913517).

Almost surely, 2^221401025 is an apocalyptic number.

221401025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221401025 is a deficient number, since it is larger than the sum of its proper divisors (64523383).

221401025 is a wasteful number, since it uses less digits than its factorization.

221401025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3653 (or 3648 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 221401025 is about 14879.5505644492. The cubic root of 221401025 is about 604.9598361425.

Adding to 221401025 its reverse (520104122), we get a palindrome (741505147).

The spelling of 221401025 in words is "two hundred twenty-one million, four hundred one thousand, twenty-five".