221357765 has 32 divisors (see below), whose sum is σ = 292190976. Its totient is φ = 160312320.

The previous prime is 221357743. The next prime is 221357803. The reversal of 221357765 is 567753122.

221357765 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221357765 - 2¹⁴ = 221341381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 259079 + ... + 259931.

It is an arithmetic number, because the mean of its divisors is an integer number (9130968).

Almost surely, 2^221357765 is an apocalyptic number.

It is an amenable number.

221357765 is a deficient number, since it is larger than the sum of its proper divisors (70833211).

221357765 is a wasteful number, since it uses less digits than its factorization.

221357765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 989.

The product of its digits is 88200, while the sum is 38.

The square root of 221357765 is about 14878.0968204942. The cubic root of 221357765 is about 604.9204321286.

The spelling of 221357765 in words is "two hundred twenty-one million, three hundred fifty-seven thousand, seven hundred sixty-five".