221071890 has 32 divisors (see below), whose sum is σ = 571386816. Its totient is φ = 54417600.

The previous prime is 221071889. The next prime is 221071891. The reversal of 221071890 is 98170122.

It is an interprime number because it is at equal distance from previous prime (221071889) and next prime (221071891).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (221071891) 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, 283036 + ... + 283815.

It is an arithmetic number, because the mean of its divisors is an integer number (17855838).

Almost surely, 2^221071890 is an apocalyptic number.

221071890 is an abundant number, since it is smaller than the sum of its proper divisors (350314926).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221071890 is a wasteful number, since it uses less digits than its factorization.

221071890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566874.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 221071890 is about 14868.4864730745. The cubic root of 221071890 is about 604.6599094903.

The spelling of 221071890 in words is "two hundred twenty-one million, seventy-one thousand, eight hundred ninety".