77121809490 has 32 divisors (see below), whose sum is σ = 201918920256. Its totient is φ = 18696196160.

The previous prime is 77121809477. The next prime is 77121809507. The reversal of 77121809490 is 9490812177.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116850897 + ... + 116851556.

It is an arithmetic number, because the mean of its divisors is an integer number (6309966258).

Almost surely, 2^77121809490 is an apocalyptic number.

77121809490 is an abundant number, since it is smaller than the sum of its proper divisors (124797110766).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77121809490 is a wasteful number, since it uses less digits than its factorization.

77121809490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233702474.

The product of its (nonzero) digits is 254016, while the sum is 48.

The spelling of 77121809490 in words is "seventy-seven billion, one hundred twenty-one million, eight hundred nine thousand, four hundred ninety".