145204021221 has 32 divisors (see below), whose sum is σ = 234587052288. Its totient is φ = 77990154240.

The previous prime is 145204021217. The next prime is 145204021223. The reversal of 145204021221 is 122120402541.

It is not a de Polignac number, because 145204021221 - 2² = 145204021217 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 145204021191 and 145204021200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145204021223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4441 + ... + 538913.

It is an arithmetic number, because the mean of its divisors is an integer number (7330845384).

Almost surely, 2^145204021221 is an apocalyptic number.

It is an amenable number.

145204021221 is a deficient number, since it is larger than the sum of its proper divisors (89383031067).

145204021221 is a wasteful number, since it uses less digits than its factorization.

145204021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535261.

The product of its (nonzero) digits is 1280, while the sum is 24.

Adding to 145204021221 its reverse (122120402541), we get a palindrome (267324423762).

The spelling of 145204021221 in words is "one hundred forty-five billion, two hundred four million, twenty-one thousand, two hundred twenty-one".