221431402 has 4 divisors (see below), whose sum is σ = 332147106. Its totient is φ = 110715700.

The previous prime is 221431367. The next prime is 221431423. The reversal of 221431402 is 204134122.

221431402 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 166952241 + 54479161 = 12921^2 + 7381^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 221431402.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55357849 + ... + 55357852.

Almost surely, 2^221431402 is an apocalyptic number.

221431402 is a deficient number, since it is larger than the sum of its proper divisors (110715704).

221431402 is a wasteful number, since it uses less digits than its factorization.

221431402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110715703.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 221431402 is about 14880.5712927965. The cubic root of 221431402 is about 604.9875024170.

Adding to 221431402 its reverse (204134122), we get a palindrome (425565524).

The spelling of 221431402 in words is "two hundred twenty-one million, four hundred thirty-one thousand, four hundred two".