77777421 has 8 divisors (see below), whose sum is σ = 108212160. Its totient is φ = 49597152.

The previous prime is 77777407. The next prime is 77777423. The reversal of 77777421 is 12477777.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 77777421 - 2¹³ = 77769229 is a prime.

It is a super-2 number, since 2×77777421² = 12098654434822482, which contains 22 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77777423) 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 in 7 ways as a sum of consecutive naturals, for example, 563536 + ... + 563673.

It is an arithmetic number, because the mean of its divisors is an integer number (13526520).

Almost surely, 2^77777421 is an apocalyptic number.

It is an amenable number.

77777421 is a deficient number, since it is larger than the sum of its proper divisors (30434739).

77777421 is a wasteful number, since it uses less digits than its factorization.

77777421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1127235.

The product of its digits is 134456, while the sum is 42.

The square root of 77777421 is about 8819.1508094601. The cubic root of 77777421 is about 426.8590689727.

The spelling of 77777421 in words is "seventy-seven million, seven hundred seventy-seven thousand, four hundred twenty-one".