531921391 has 4 divisors (see below), whose sum is σ = 555048432. Its totient is φ = 508794352.

The previous prime is 531921389. The next prime is 531921427. The reversal of 531921391 is 193129135.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 531921391 - 2¹ = 531921389 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 (531921301) 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, 11563486 + ... + 11563531.

It is an arithmetic number, because the mean of its divisors is an integer number (138762108).

Almost surely, 2^531921391 is an apocalyptic number.

531921391 is a deficient number, since it is larger than the sum of its proper divisors (23127041).

531921391 is a wasteful number, since it uses less digits than its factorization.

531921391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23127040.

The product of its digits is 7290, while the sum is 34.

The square root of 531921391 is about 23063.4210601983. The cubic root of 531921391 is about 810.2439904102.

The spelling of 531921391 in words is "five hundred thirty-one million, nine hundred twenty-one thousand, three hundred ninety-one".