2187475981 has 2 divisors, whose sum is σ = 2187475982. Its totient is φ = 2187475980.

The previous prime is 2187475963. The next prime is 2187475999. The reversal of 2187475981 is 1895747812.

It is a balanced prime because it is at equal distance from previous prime (2187475963) and next prime (2187475999).

It can be written as a sum of positive squares in only one way, i.e., 1280924100 + 906551881 = 35790^2 + 30109^2 .

It is a cyclic number.

It is not a de Polignac number, because 2187475981 - 2²⁷ = 2053258253 is a prime.

It is a super-2 number, since 2×2187475981² = 9570102334903824722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2187475181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1093737990 + 1093737991.

It is an arithmetic number, because the mean of its divisors is an integer number (1093737991).

Almost surely, 2^2187475981 is an apocalyptic number.

It is an amenable number.

2187475981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2187475981 is an equidigital number, since it uses as much as digits as its factorization.

2187475981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1128960, while the sum is 52.

The square root of 2187475981 is about 46770.4605600586. The cubic root of 2187475981 is about 1298.1187742638.

The spelling of 2187475981 in words is "two billion, one hundred eighty-seven million, four hundred seventy-five thousand, nine hundred eighty-one".