145121421505 has 4 divisors (see below), whose sum is σ = 174145705812. Its totient is φ = 116097137200.

The previous prime is 145121421503. The next prime is 145121421551. The reversal of 145121421505 is 505124121541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505124121541 = 13 ⋅38855701657.

It can be written as a sum of positive squares in 2 ways, for example, as 115942974016 + 29178447489 = 340504^2 + 170817^2 .

It is not a de Polignac number, because 145121421505 - 2¹ = 145121421503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145121421503) 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, 14512142146 + ... + 14512142155.

It is an arithmetic number, because the mean of its divisors is an integer number (43536426453).

Almost surely, 2^145121421505 is an apocalyptic number.

It is an amenable number.

145121421505 is a deficient number, since it is larger than the sum of its proper divisors (29024284307).

145121421505 is an equidigital number, since it uses as much as digits as its factorization.

145121421505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29024284306.

The product of its (nonzero) digits is 8000, while the sum is 31.

The spelling of 145121421505 in words is "one hundred forty-five billion, one hundred twenty-one million, four hundred twenty-one thousand, five hundred five".