72781551187 has 16 divisors (see below), whose sum is σ = 78348533760. Its totient is φ = 67431668832.

The previous prime is 72781551151. The next prime is 72781551217. The reversal of 72781551187 is 78115518727.

It is a de Polignac number, because none of the positive numbers 2^k-72781551187 is a prime.

It is a super-2 number, since 2×72781551187² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72781551137) 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, 1987 + ... + 381532.

It is an arithmetic number, because the mean of its divisors is an integer number (4896783360).

Almost surely, 2^72781551187 is an apocalyptic number.

72781551187 is a deficient number, since it is larger than the sum of its proper divisors (5566982573).

72781551187 is a wasteful number, since it uses less digits than its factorization.

72781551187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383802.

The product of its digits is 1097600, while the sum is 52.

The spelling of 72781551187 in words is "seventy-two billion, seven hundred eighty-one million, five hundred fifty-one thousand, one hundred eighty-seven".