221753402649 has 63 divisors (see below), whose sum is σ = 337685936133. Its totient is φ = 145555470072.

The previous prime is 221753402627. The next prime is 221753402743. The reversal of 221753402649 is 946204357122.

The square root of 221753402649 is 470907.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 221753402649 - 2²⁷ = 221619184921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221753402149) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 1360450242 + ... + 1360450404.

Almost surely, 2^221753402649 is an apocalyptic number.

221753402649 is the 470907-th square number.

221753402649 is the 235454-th centered octagonal number.

It is an amenable number.

221753402649 is a deficient number, since it is larger than the sum of its proper divisors (115932533484).

221753402649 is an frugal number, since it uses more digits than its factorization.

221753402649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The spelling of 221753402649 in words is "two hundred twenty-one billion, seven hundred fifty-three million, four hundred two thousand, six hundred forty-nine".