775541621 has 2 divisors, whose sum is σ = 775541622. Its totient is φ = 775541620.

The previous prime is 775541521. The next prime is 775541653. The reversal of 775541621 is 126145577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 760987396 + 14554225 = 27586^2 + 3815^2 .

It is an emirp because it is prime and its reverse (126145577) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 775541621 - 2¹⁴ = 775525237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (775541681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 387770810 + 387770811.

It is an arithmetic number, because the mean of its divisors is an integer number (387770811).

Almost surely, 2^775541621 is an apocalyptic number.

It is an amenable number.

775541621 is a deficient number, since it is larger than the sum of its proper divisors (1).

775541621 is an equidigital number, since it uses as much as digits as its factorization.

775541621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58800, while the sum is 38.

The square root of 775541621 is about 27848.5479154659. The cubic root of 775541621 is about 918.7592051402.

The spelling of 775541621 in words is "seven hundred seventy-five million, five hundred forty-one thousand, six hundred twenty-one".