221948657 has 4 divisors (see below), whose sum is σ = 253655616. Its totient is φ = 190241700.

The previous prime is 221948653. The next prime is 221948659. The reversal of 221948657 is 756849122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221948657 - 2² = 221948653 is a prime.

It is a super-2 number, since 2×221948657² = 98522412688207298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221948653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15853469 + ... + 15853482.

It is an arithmetic number, because the mean of its divisors is an integer number (63413904).

Almost surely, 2^221948657 is an apocalyptic number.

It is an amenable number.

221948657 is a deficient number, since it is larger than the sum of its proper divisors (31706959).

221948657 is an equidigital number, since it uses as much as digits as its factorization.

221948657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31706958.

The product of its digits is 241920, while the sum is 44.

The square root of 221948657 is about 14897.9413678535. The cubic root of 221948657 is about 605.4582117160.

The spelling of 221948657 in words is "two hundred twenty-one million, nine hundred forty-eight thousand, six hundred fifty-seven".