77013021221 has 8 divisors (see below), whose sum is σ = 80374778880. Its totient is φ = 73652377392.

The previous prime is 77013021167. The next prime is 77013021227. The reversal of 77013021221 is 12212031077.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77013021221 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 (77013021227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135590 + ... + 415223.

It is an arithmetic number, because the mean of its divisors is an integer number (10046847360).

Almost surely, 2^77013021221 is an apocalyptic number.

It is an amenable number.

77013021221 is a deficient number, since it is larger than the sum of its proper divisors (3361757659).

77013021221 is a wasteful number, since it uses less digits than its factorization.

77013021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556915.

The product of its (nonzero) digits is 1176, while the sum is 26.

Adding to 77013021221 its reverse (12212031077), we get a palindrome (89225052298).

The spelling of 77013021221 in words is "seventy-seven billion, thirteen million, twenty-one thousand, two hundred twenty-one".