221061819 has 16 divisors (see below), whose sum is σ = 321914880. Its totient is φ = 133822560.

The previous prime is 221061817. The next prime is 221061833. The reversal of 221061819 is 918160122.

It is a happy number.

It is not a de Polignac number, because 221061819 - 2¹ = 221061817 is a prime.

It is a super-2 number, since 2×221061819² = 97736655639177522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221061811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29542 + ... + 36260.

It is an arithmetic number, because the mean of its divisors is an integer number (20119680).

Almost surely, 2^221061819 is an apocalyptic number.

221061819 is a deficient number, since it is larger than the sum of its proper divisors (100853061).

221061819 is a wasteful number, since it uses less digits than its factorization.

221061819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7730.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 221061819 is about 14868.1477999111. The cubic root of 221061819 is about 604.6507275263.

The spelling of 221061819 in words is "two hundred twenty-one million, sixty-one thousand, eight hundred nineteen".