77432406421 has 4 divisors (see below), whose sum is σ = 77439542752. Its totient is φ = 77425270092.

The previous prime is 77432406419. The next prime is 77432406433. The reversal of 77432406421 is 12460423477.

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 77432406421 - 2¹ = 77432406419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77432406451) 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, 3551865 + ... + 3573598.

It is an arithmetic number, because the mean of its divisors is an integer number (19359885688).

Almost surely, 2^77432406421 is an apocalyptic number.

It is an amenable number.

77432406421 is a deficient number, since it is larger than the sum of its proper divisors (7136331).

77432406421 is a wasteful number, since it uses less digits than its factorization.

77432406421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7136330.

The product of its (nonzero) digits is 225792, while the sum is 40.

Adding to 77432406421 its reverse (12460423477), we get a palindrome (89892829898).

The spelling of 77432406421 in words is "seventy-seven billion, four hundred thirty-two million, four hundred six thousand, four hundred twenty-one".