77111621 has 2 divisors, whose sum is σ = 77111622. Its totient is φ = 77111620.

The previous prime is 77111603. The next prime is 77111641. The reversal of 77111621 is 12611177.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75498721 + 1612900 = 8689^2 + 1270^2 .

It is an emirp because it is prime and its reverse (12611177) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77111621 - 2¹⁴ = 77095237 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77111641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38555810 + 38555811.

It is an arithmetic number, because the mean of its divisors is an integer number (38555811).

Almost surely, 2^77111621 is an apocalyptic number.

It is an amenable number.

77111621 is a deficient number, since it is larger than the sum of its proper divisors (1).

77111621 is an equidigital number, since it uses as much as digits as its factorization.

77111621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 588, while the sum is 26.

The square root of 77111621 is about 8781.3222808413. The cubic root of 77111621 is about 425.6375593566.

Adding to 77111621 its reverse (12611177), we get a palindrome (89722798).

The spelling of 77111621 in words is "seventy-seven million, one hundred eleven thousand, six hundred twenty-one".