2145691 has 8 divisors (see below), whose sum is σ = 2225664. Its totient is φ = 2067240.

The previous prime is 2145683. The next prime is 2145707. The reversal of 2145691 is 1965412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2145691 - 2³ = 2145683 is a prime.

It is a Duffinian number.

2145691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2145631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3016 + ... + 3658.

It is an arithmetic number, because the mean of its divisors is an integer number (278208).

2^2145691 is an apocalyptic number.

2145691 is a deficient number, since it is larger than the sum of its proper divisors (79973).

2145691 is an equidigital number, since it uses as much as digits as its factorization.

2145691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761.

The product of its digits is 2160, while the sum is 28.

The square root of 2145691 is about 1464.8177361023. The cubic root of 2145691 is about 128.9800061155.

The spelling of 2145691 in words is "two million, one hundred forty-five thousand, six hundred ninety-one".