145212021 has 20 divisors (see below), whose sum is σ = 217255500. Its totient is φ = 96659136.

The previous prime is 145211993. The next prime is 145212047. The reversal of 145212021 is 120212541.

145212021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 82628100 + 62583921 = 9090^2 + 7911^2 .

It is not a de Polignac number, because 145212021 - 2¹³ = 145203829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 145211985 and 145212003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145212071) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 84115 + ... + 85823.

It is an arithmetic number, because the mean of its divisors is an integer number (10862775).

Almost surely, 2^145212021 is an apocalyptic number.

It is an amenable number.

145212021 is a deficient number, since it is larger than the sum of its proper divisors (72043479).

145212021 is a wasteful number, since it uses less digits than its factorization.

145212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2770 (or 2761 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 145212021 is about 12050.3950557648. The cubic root of 145212021 is about 525.6147248330.

Adding to 145212021 its reverse (120212541), we get a palindrome (265424562).

The spelling of 145212021 in words is "one hundred forty-five million, two hundred twelve thousand, twenty-one".