313540021 has 4 divisors (see below), whose sum is σ = 314561632. Its totient is φ = 312518412.

The previous prime is 313539973. The next prime is 313540039. The reversal of 313540021 is 120045313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120045313 = 17 ⋅7061489.

It is a cyclic number.

It is not a de Polignac number, because 313540021 - 2¹⁹ = 313015733 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 (313540091) 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, 510345 + ... + 510958.

It is an arithmetic number, because the mean of its divisors is an integer number (78640408).

Almost surely, 2^313540021 is an apocalyptic number.

It is an amenable number.

313540021 is a deficient number, since it is larger than the sum of its proper divisors (1021611).

313540021 is a wasteful number, since it uses less digits than its factorization.

313540021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1021610.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 313540021 is about 17707.0613315705. The cubic root of 313540021 is about 679.3563842376.

Adding to 313540021 its reverse (120045313), we get a palindrome (433585334).

The spelling of 313540021 in words is "three hundred thirteen million, five hundred forty thousand, twenty-one".