221786242 has 4 divisors (see below), whose sum is σ = 332679366. Its totient is φ = 110893120.

The previous prime is 221786237. The next prime is 221786249. The reversal of 221786242 is 242687122.

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

It can be written as a sum of positive squares in only one way, i.e., 152547201 + 69239041 = 12351^2 + 8321^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221786198 and 221786207.

It is not an unprimeable number, because it can be changed into a prime (221786249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55446559 + ... + 55446562.

Almost surely, 2^221786242 is an apocalyptic number.

221786242 is a deficient number, since it is larger than the sum of its proper divisors (110893124).

221786242 is a wasteful number, since it uses less digits than its factorization.

221786242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110893123.

The product of its digits is 21504, while the sum is 34.

The square root of 221786242 is about 14892.4894493835. The cubic root of 221786242 is about 605.3104906277.

The spelling of 221786242 in words is "two hundred twenty-one million, seven hundred eighty-six thousand, two hundred forty-two".