2151993 has 4 divisors (see below), whose sum is σ = 2869328. Its totient is φ = 1434660.

The previous prime is 2151991. The next prime is 2152001. The reversal of 2151993 is 3991512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2151993 - 2¹ = 2151991 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2151993.

It is not an unprimeable number, because it can be changed into a prime (2151991) 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, 358663 + ... + 358668.

It is an arithmetic number, because the mean of its divisors is an integer number (717332).

2^2151993 is an apocalyptic number.

It is an amenable number.

2151993 is a deficient number, since it is larger than the sum of its proper divisors (717335).

2151993 is an equidigital number, since it uses as much as digits as its factorization.

2151993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717334.

The product of its digits is 2430, while the sum is 30.

The square root of 2151993 is about 1466.9672797987. The cubic root of 2151993 is about 129.1061562335.

It can be divided in two parts, 21519 and 93, that added together give a palindrome (21612).

The spelling of 2151993 in words is "two million, one hundred fifty-one thousand, nine hundred ninety-three".