77888747021 has 8 divisors (see below), whose sum is σ = 78314213760. Its totient is φ = 77464110528.

The previous prime is 77888746973. The next prime is 77888747047. The reversal of 77888747021 is 12074788877.

It is a happy number.

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-77888747021 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 (77888747621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18956 + ... + 395141.

It is an arithmetic number, because the mean of its divisors is an integer number (9789276720).

Almost surely, 2^77888747021 is an apocalyptic number.

It is an amenable number.

77888747021 is a deficient number, since it is larger than the sum of its proper divisors (425466739).

77888747021 is a wasteful number, since it uses less digits than its factorization.

77888747021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415123.

The product of its (nonzero) digits is 9834496, while the sum is 59.

The spelling of 77888747021 in words is "seventy-seven billion, eight hundred eighty-eight million, seven hundred forty-seven thousand, twenty-one".