77013002020021 has 4 divisors (see below), whose sum is σ = 81543178609452. Its totient is φ = 72482825430592.

The previous prime is 77013002019913. The next prime is 77013002020061. The reversal of 77013002020021 is 12002020031077.

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 60887043090225 + 16125958929796 = 7803015^2 + 4015714^2 .

It is a cyclic number.

It is not a de Polignac number, because 77013002020021 - 2²¹ = 77012999922869 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 (77013002020061) 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, 2265088294690 + ... + 2265088294723.

It is an arithmetic number, because the mean of its divisors is an integer number (20385794652363).

Almost surely, 2^{77013002020021} is an apocalyptic number.

It is an amenable number.

77013002020021 is a deficient number, since it is larger than the sum of its proper divisors (4530176589431).

77013002020021 is a wasteful number, since it uses less digits than its factorization.

77013002020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4530176589430.

The product of its (nonzero) digits is 1176, while the sum is 25.

Adding to 77013002020021 its reverse (12002020031077), we get a palindrome (89015022051098).

The spelling of 77013002020021 in words is "seventy-seven trillion, thirteen billion, two million, twenty thousand, twenty-one".