133515421 has 4 divisors (see below), whose sum is σ = 143785852. Its totient is φ = 123244992.

The previous prime is 133515409. The next prime is 133515439. The reversal of 133515421 is 124515331.

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: 124515331 = 293 ⋅424967.

It can be written as a sum of positive squares in 2 ways, for example, as 33235225 + 100280196 = 5765^2 + 10014^2 .

It is not a de Polignac number, because 133515421 - 2¹⁵ = 133482653 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 (133515401) 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, 5135196 + ... + 5135221.

It is an arithmetic number, because the mean of its divisors is an integer number (35946463).

Almost surely, 2^133515421 is an apocalyptic number.

It is an amenable number.

133515421 is a deficient number, since it is larger than the sum of its proper divisors (10270431).

133515421 is a wasteful number, since it uses less digits than its factorization.

133515421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10270430.

The product of its digits is 1800, while the sum is 25.

The square root of 133515421 is about 11554.8873209564. The cubic root of 133515421 is about 511.1054083047.

The spelling of 133515421 in words is "one hundred thirty-three million, five hundred fifteen thousand, four hundred twenty-one".