77140621 has 2 divisors, whose sum is σ = 77140622. Its totient is φ = 77140620.

The previous prime is 77140619. The next prime is 77140631. The reversal of 77140621 is 12604177.

77140621 = 6210² + 6211².

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38576521 + 38564100 = 6211^2 + 6210^2 .

It is a cyclic number.

It is not a de Polignac number, because 77140621 - 2¹ = 77140619 is a prime.

Together with 77140619, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 77140621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77140631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38570310 + 38570311.

It is an arithmetic number, because the mean of its divisors is an integer number (38570311).

Almost surely, 2^77140621 is an apocalyptic number.

77140621 is the 6211-st centered square number.

It is an amenable number.

77140621 is a deficient number, since it is larger than the sum of its proper divisors (1).

77140621 is an equidigital number, since it uses as much as digits as its factorization.

77140621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 77140621 is about 8782.9733575823. The cubic root of 77140621 is about 425.6909103389.

Adding to 77140621 its reverse (12604177), we get a palindrome (89744798).

The spelling of 77140621 in words is "seventy-seven million, one hundred forty thousand, six hundred twenty-one".