221021402 has 16 divisors (see below), whose sum is σ = 381880320. Its totient is φ = 93976848.

The previous prime is 221021399. The next prime is 221021459. The reversal of 221021402 is 204120122.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60377 + ... + 63932.

It is an arithmetic number, because the mean of its divisors is an integer number (23867520).

Almost surely, 2^221021402 is an apocalyptic number.

221021402 is a deficient number, since it is larger than the sum of its proper divisors (160858918).

221021402 is a wasteful number, since it uses less digits than its factorization.

221021402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124445.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 221021402 is about 14866.7885570489. The cubic root of 221021402 is about 604.6138756055.

Adding to 221021402 its reverse (204120122), we get a palindrome (425141524).

The spelling of 221021402 in words is "two hundred twenty-one million, twenty-one thousand, four hundred two".