145221653 has 4 divisors (see below), whose sum is σ = 145324428. Its totient is φ = 145118880.

The previous prime is 145221649. The next prime is 145221673. The reversal of 145221653 is 356122541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 356122541 = 7639 ⋅46619.

It can be written as a sum of positive squares in 2 ways, for example, as 127396369 + 17825284 = 11287^2 + 4222^2 .

It is a cyclic number.

It is not a de Polignac number, because 145221653 - 2² = 145221649 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145221623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49238 + ... + 52103.

It is an arithmetic number, because the mean of its divisors is an integer number (36331107).

Almost surely, 2^145221653 is an apocalyptic number.

It is an amenable number.

145221653 is a deficient number, since it is larger than the sum of its proper divisors (102775).

145221653 is a wasteful number, since it uses less digits than its factorization.

145221653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102774.

The product of its digits is 7200, while the sum is 29.

The square root of 145221653 is about 12050.7947040849. The cubic root of 145221653 is about 525.6263460222.

The spelling of 145221653 in words is "one hundred forty-five million, two hundred twenty-one thousand, six hundred fifty-three".