221620075 has 24 divisors (see below), whose sum is σ = 292561632. Its totient is φ = 165957120.

The previous prime is 221620073. The next prime is 221620081. The reversal of 221620075 is 570026122.

It is not a de Polignac number, because 221620075 - 2¹ = 221620073 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221620073) 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 23 ways as a sum of consecutive naturals, for example, 82402 + ... + 85048.

It is an arithmetic number, because the mean of its divisors is an integer number (12190068).

Almost surely, 2^221620075 is an apocalyptic number.

221620075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

221620075 is a deficient number, since it is larger than the sum of its proper divisors (70941557).

221620075 is a wasteful number, since it uses less digits than its factorization.

221620075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2871 (or 2866 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 221620075 is about 14886.9095180968. The cubic root of 221620075 is about 605.1592823330.

Adding to 221620075 its reverse (570026122), we get a palindrome (791646197).

The spelling of 221620075 in words is "two hundred twenty-one million, six hundred twenty thousand, seventy-five".