76778421 has 4 divisors (see below), whose sum is σ = 102371232. Its totient is φ = 51185612.

The previous prime is 76778419. The next prime is 76778459. The reversal of 76778421 is 12487767.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 76778421 - 2¹ = 76778419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76778461) 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, 12796401 + ... + 12796406.

It is an arithmetic number, because the mean of its divisors is an integer number (25592808).

Almost surely, 2^76778421 is an apocalyptic number.

It is an amenable number.

76778421 is a deficient number, since it is larger than the sum of its proper divisors (25592811).

76778421 is a wasteful number, since it uses less digits than its factorization.

76778421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25592810.

The product of its digits is 131712, while the sum is 42.

The square root of 76778421 is about 8762.3296559762. The cubic root of 76778421 is about 425.0236129902.

The spelling of 76778421 in words is "seventy-six million, seven hundred seventy-eight thousand, four hundred twenty-one".