77169041921 has 4 divisors (see below), whose sum is σ = 78434108244. Its totient is φ = 75903975600.

The previous prime is 77169041909. The next prime is 77169041933. The reversal of 77169041921 is 12914096177.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (77169041909) and next prime (77169041933).

It can be written as a sum of positive squares in 2 ways, for example, as 29049793600 + 48119248321 = 170440^2 + 219361^2 .

It is a cyclic number.

It is not a de Polignac number, because 77169041921 - 2¹⁴ = 77169025537 is a prime.

It is a super-2 number, since 2×77169041921² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77169041021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 632533070 + ... + 632533191.

It is an arithmetic number, because the mean of its divisors is an integer number (19608527061).

Almost surely, 2^77169041921 is an apocalyptic number.

It is an amenable number.

77169041921 is a deficient number, since it is larger than the sum of its proper divisors (1265066323).

77169041921 is a wasteful number, since it uses less digits than its factorization.

77169041921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1265066322.

The product of its (nonzero) digits is 190512, while the sum is 47.

The spelling of 77169041921 in words is "seventy-seven billion, one hundred sixty-nine million, forty-one thousand, nine hundred twenty-one".