75431621 has 2 divisors, whose sum is σ = 75431622. Its totient is φ = 75431620.

The previous prime is 75431617. The next prime is 75431623. The reversal of 75431621 is 12613457.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39551521 + 35880100 = 6289^2 + 5990^2 .

It is an emirp because it is prime and its reverse (12613457) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 75431621 - 2² = 75431617 is a prime.

Together with 75431623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75431623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37715810 + 37715811.

It is an arithmetic number, because the mean of its divisors is an integer number (37715811).

Almost surely, 2^75431621 is an apocalyptic number.

It is an amenable number.

75431621 is a deficient number, since it is larger than the sum of its proper divisors (1).

75431621 is an equidigital number, since it uses as much as digits as its factorization.

75431621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 29.

The square root of 75431621 is about 8685.1379378799. The cubic root of 75431621 is about 422.5237707060.

The spelling of 75431621 in words is "seventy-five million, four hundred thirty-one thousand, six hundred twenty-one".