221265001 has 4 divisors (see below), whose sum is σ = 222880212. Its totient is φ = 219649792.

The previous prime is 221264999. The next prime is 221265007. The reversal of 221265001 is 100562122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 76038400 + 145226601 = 8720^2 + 12051^2 .

It is a cyclic number.

It is not a de Polignac number, because 221265001 - 2¹ = 221264999 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221265001.

It is not an unprimeable number, because it can be changed into a prime (221265007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807400 + ... + 807673.

It is an arithmetic number, because the mean of its divisors is an integer number (55720053).

Almost surely, 2^221265001 is an apocalyptic number.

It is an amenable number.

221265001 is a deficient number, since it is larger than the sum of its proper divisors (1615211).

221265001 is a wasteful number, since it uses less digits than its factorization.

221265001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615210.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 221265001 is about 14874.9790251953. The cubic root of 221265001 is about 604.8359193499.

The spelling of 221265001 in words is "two hundred twenty-one million, two hundred sixty-five thousand, one".