77661469 has 2 divisors, whose sum is σ = 77661470. Its totient is φ = 77661468.

The previous prime is 77661461. The next prime is 77661473. The reversal of 77661469 is 96416677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77616100 + 45369 = 8810^2 + 213^2 .

It is a cyclic number.

It is not a de Polignac number, because 77661469 - 2³ = 77661461 is a prime.

It is a super-2 number, since 2×77661469² = 12062607534475922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77661461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38830734 + 38830735.

It is an arithmetic number, because the mean of its divisors is an integer number (38830735).

Almost surely, 2^77661469 is an apocalyptic number.

It is an amenable number.

77661469 is a deficient number, since it is larger than the sum of its proper divisors (1).

77661469 is an equidigital number, since it uses as much as digits as its factorization.

77661469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 381024, while the sum is 46.

The square root of 77661469 is about 8812.5744819547. The cubic root of 77661469 is about 426.6468403738.

The spelling of 77661469 in words is "seventy-seven million, six hundred sixty-one thousand, four hundred sixty-nine".