221620025 has 12 divisors (see below), whose sum is σ = 299791824. Its totient is φ = 161178000.

The previous prime is 221620013. The next prime is 221620027. The reversal of 221620025 is 520026122.

It is a de Polignac number, because none of the positive numbers 2^k-221620025 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221619979 and 221620006.

It is not an unprimeable number, because it can be changed into a prime (221620027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 402671 + ... + 403220.

It is an arithmetic number, because the mean of its divisors is an integer number (24982652).

Almost surely, 2^221620025 is an apocalyptic number.

221620025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221620025 is a deficient number, since it is larger than the sum of its proper divisors (78171799).

221620025 is a wasteful number, since it uses less digits than its factorization.

221620025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805912 (or 805907 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 221620025 is about 14886.9078387689. The cubic root of 221620025 is about 605.1592368228.

Adding to 221620025 its reverse (520026122), we get a palindrome (741646147).

The spelling of 221620025 in words is "two hundred twenty-one million, six hundred twenty thousand, twenty-five".