221001023 has 4 divisors (see below), whose sum is σ = 223146768. Its totient is φ = 218855280.

The previous prime is 221000981. The next prime is 221001031. The reversal of 221001023 is 320100122.

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: 320100122 = 2 ⋅160050061.

It is a cyclic number.

It is not a de Polignac number, because 221001023 - 2⁶ = 221000959 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221000995 and 221001013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1072718 + ... + 1072923.

It is an arithmetic number, because the mean of its divisors is an integer number (55786692).

Almost surely, 2^221001023 is an apocalyptic number.

221001023 is a deficient number, since it is larger than the sum of its proper divisors (2145745).

221001023 is a wasteful number, since it uses less digits than its factorization.

221001023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2145744.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 221001023 is about 14866.1031544921. The cubic root of 221001023 is about 604.5952924807.

Adding to 221001023 its reverse (320100122), we get a palindrome (541101145).

Subtracting 221001023 from its reverse (320100122), we obtain a palindrome (99099099).

The spelling of 221001023 in words is "two hundred twenty-one million, one thousand, twenty-three".