2191723425 has 18 divisors (see below), whose sum is σ = 3925620582. Its totient is φ = 1168919040.

The previous prime is 2191723423. The next prime is 2191723427. The reversal of 2191723425 is 5243271912.

2191723425 is a `hidden beast` number, since 219 + 17 + 2 + 3 + 425 = 666.

It is an interprime number because it is at equal distance from previous prime (2191723423) and next prime (2191723427).

It can be written as a sum of positive squares in 3 ways, for example, as 234457344 + 1957266081 = 15312^2 + 44241^2 .

It is not a de Polignac number, because 2191723425 - 2¹ = 2191723423 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2191723425.

It is not an unprimeable number, because it can be changed into a prime (2191723421) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4870272 + ... + 4870721.

Almost surely, 2^2191723425 is an apocalyptic number.

2191723425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2191723425 is a deficient number, since it is larger than the sum of its proper divisors (1733897157).

2191723425 is a wasteful number, since it uses less digits than its factorization.

2191723425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9741009 (or 9741001 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 2191723425 is about 46815.8458750881. The cubic root of 2191723425 is about 1298.9584211188.

The spelling of 2191723425 in words is "two billion, one hundred ninety-one million, seven hundred twenty-three thousand, four hundred twenty-five".