3781765221 has 24 divisors (see below), whose sum is σ = 5477737536. Its totient is φ = 2319707520.

The previous prime is 3781765199. The next prime is 3781765231. The reversal of 3781765221 is 1225671873.

It is not a de Polignac number, because 3781765221 - 2¹³ = 3781757029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3781765231) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146776 + ... + 170606.

It is an arithmetic number, because the mean of its divisors is an integer number (228239064).

Almost surely, 2^3781765221 is an apocalyptic number.

It is an amenable number.

3781765221 is a deficient number, since it is larger than the sum of its proper divisors (1695972315).

3781765221 is a wasteful number, since it uses less digits than its factorization.

3781765221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24173 (or 24160 counting only the distinct ones).

The product of its digits is 141120, while the sum is 42.

The square root of 3781765221 is about 61496.0585810180. The cubic root of 3781765221 is about 1557.9906769365.

The spelling of 3781765221 in words is "three billion, seven hundred eighty-one million, seven hundred sixty-five thousand, two hundred twenty-one".