77642045212421 has 4 divisors (see below), whose sum is σ = 77643992290572. Its totient is φ = 77640098134272.

The previous prime is 77642045212409. The next prime is 77642045212469. The reversal of 77642045212421 is 12421254024677.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15603013504225 + 62039031708196 = 3950065^2 + 7876486^2 .

It is a cyclic number.

It is not a de Polignac number, because 77642045212421 - 2⁶ = 77642045212357 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 (77642045212471) 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, 973479260 + ... + 973559013.

It is an arithmetic number, because the mean of its divisors is an integer number (19410998072643).

Almost surely, 2^{77642045212421} is an apocalyptic number.

It is an amenable number.

77642045212421 is a deficient number, since it is larger than the sum of its proper divisors (1947078151).

77642045212421 is a wasteful number, since it uses less digits than its factorization.

77642045212421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1947078150.

The product of its (nonzero) digits is 1505280, while the sum is 47.

The spelling of 77642045212421 in words is "seventy-seven trillion, six hundred forty-two billion, forty-five million, two hundred twelve thousand, four hundred twenty-one".