77490521 has 2 divisors, whose sum is σ = 77490522. Its totient is φ = 77490520.

The previous prime is 77490499. The next prime is 77490529. The reversal of 77490521 is 12509477.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58446025 + 19044496 = 7645^2 + 4364^2 .

It is a cyclic number.

It is not a de Polignac number, because 77490521 - 2¹⁸ = 77228377 is a prime.

It is not a weakly prime, because it can be changed into another prime (77490529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38745260 + 38745261.

It is an arithmetic number, because the mean of its divisors is an integer number (38745261).

Almost surely, 2^77490521 is an apocalyptic number.

It is an amenable number.

77490521 is a deficient number, since it is larger than the sum of its proper divisors (1).

77490521 is an equidigital number, since it uses as much as digits as its factorization.

77490521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 77490521 is about 8802.8700433438. The cubic root of 77490521 is about 426.3335661730. Note that the first 3 decimals are identical.

Adding to 77490521 its reverse (12509477), we get a palindrome (89999998).

The spelling of 77490521 in words is "seventy-seven million, four hundred ninety thousand, five hundred twenty-one".