2187101781 has 12 divisors (see below), whose sum is σ = 3160211808. Its totient is φ = 1457576424.

The previous prime is 2187101771. The next prime is 2187101831. The reversal of 2187101781 is 1871017812.

It is not a de Polignac number, because 2187101781 - 2¹⁰ = 2187100757 is a prime.

It is a super-2 number, since 2×2187101781² = 9566828400906743922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2187101771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11665 + ... + 67158.

It is an arithmetic number, because the mean of its divisors is an integer number (263350984).

Almost surely, 2^2187101781 is an apocalyptic number.

It is an amenable number.

2187101781 is a deficient number, since it is larger than the sum of its proper divisors (973110027).

2187101781 is a wasteful number, since it uses less digits than its factorization.

2187101781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81912 (or 81909 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 36.

The square root of 2187101781 is about 46766.4600007313. The cubic root of 2187101781 is about 1298.0447492611.

The spelling of 2187101781 in words is "two billion, one hundred eighty-seven million, one hundred one thousand, seven hundred eighty-one".