72111987261 has 16 divisors (see below), whose sum is σ = 106872264000. Its totient is φ = 48056797584.

The previous prime is 72111987191. The next prime is 72111987293. The reversal of 72111987261 is 16278911127.

It is a happy number.

It is not a de Polignac number, because 72111987261 - 2¹⁷ = 72111856189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72111988261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 421906 + ... + 567651.

It is an arithmetic number, because the mean of its divisors is an integer number (6679516500).

Almost surely, 2^72111987261 is an apocalyptic number.

It is an amenable number.

72111987261 is a deficient number, since it is larger than the sum of its proper divisors (34760276739).

72111987261 is a wasteful number, since it uses less digits than its factorization.

72111987261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992265 (or 992259 counting only the distinct ones).

The product of its digits is 84672, while the sum is 45.

The spelling of 72111987261 in words is "seventy-two billion, one hundred eleven million, nine hundred eighty-seven thousand, two hundred sixty-one".