221001994 has 4 divisors (see below), whose sum is σ = 331502994. Its totient is φ = 110500996.

The previous prime is 221001967. The next prime is 221002003. The reversal of 221001994 is 499100122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 499100122 = 2 ⋅249550061.

It can be written as a sum of positive squares in only one way, i.e., 127396369 + 93605625 = 11287^2 + 9675^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55250497 + ... + 55250500.

Almost surely, 2^221001994 is an apocalyptic number.

221001994 is a deficient number, since it is larger than the sum of its proper divisors (110501000).

221001994 is a wasteful number, since it uses less digits than its factorization.

221001994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110500999.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 221001994 is about 14866.1358126448. The cubic root of 221001994 is about 604.5961779384.

The spelling of 221001994 in words is "two hundred twenty-one million, one thousand, nine hundred ninety-four".