77150121972 has 384 divisors, whose sum is σ = 239303393280. Its totient is φ = 18762624000.

The previous prime is 77150121953. The next prime is 77150122001. The reversal of 77150121972 is 27912105177.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 210218133 + ... + 210218499.

It is an arithmetic number, because the mean of its divisors is an integer number (623185920).

Almost surely, 2^77150121972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77150121972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119651696640).

77150121972 is an abundant number, since it is smaller than the sum of its proper divisors (162153271308).

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

77150121972 is a wasteful number, since it uses less digits than its factorization.

77150121972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 641 counting only the distinct ones).

The product of its (nonzero) digits is 61740, while the sum is 42.

The spelling of 77150121972 in words is "seventy-seven billion, one hundred fifty million, one hundred twenty-one thousand, nine hundred seventy-two".