2181954001 has 4 divisors (see below), whose sum is σ = 2182859172. Its totient is φ = 2181048832.

The previous prime is 2181953971. The next prime is 2181954109. The reversal of 2181954001 is 1004591812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1051380625 + 1130573376 = 32425^2 + 33624^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181954001 - 2¹¹ = 2181951953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181954601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 448960 + ... + 453793.

It is an arithmetic number, because the mean of its divisors is an integer number (545714793).

Almost surely, 2^2181954001 is an apocalyptic number.

It is an amenable number.

2181954001 is a deficient number, since it is larger than the sum of its proper divisors (905171).

2181954001 is an equidigital number, since it uses as much as digits as its factorization.

2181954001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905170.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 2181954001 is about 46711.3904845488. The cubic root of 2181954001 is about 1297.0255468574.

The spelling of 2181954001 in words is "two billion, one hundred eighty-one million, nine hundred fifty-four thousand, one".