77243897220 has 384 divisors, whose sum is σ = 271947497472. Its totient is φ = 15975014400.

The previous prime is 77243897191. The next prime is 77243897221. The reversal of 77243897220 is 2279834277.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (77243897221) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 36077350 + ... + 36079490.

It is an arithmetic number, because the mean of its divisors is an integer number (708196608).

Almost surely, 2^77243897220 is an apocalyptic number.

77243897220 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77243897220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135973748736).

77243897220 is an abundant number, since it is smaller than the sum of its proper divisors (194703600252).

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

77243897220 is a wasteful number, since it uses less digits than its factorization.

77243897220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371 (or 2369 counting only the distinct ones).

The product of its (nonzero) digits is 2370816, while the sum is 51.

The spelling of 77243897220 in words is "seventy-seven billion, two hundred forty-three million, eight hundred ninety-seven thousand, two hundred twenty".