2151994 has 16 divisors (see below), whose sum is σ = 3571848. Its totient is φ = 965952.

The previous prime is 2151991. The next prime is 2152001. The reversal of 2151994 is 4991512.

It can be written as a sum of positive squares in 4 ways, for example, as 2064969 + 87025 = 1437^2 + 295^2 .

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 7 ways as a sum of consecutive naturals, for example, 157 + ... + 2080.

2^2151994 is an apocalyptic number.

2151994 is a deficient number, since it is larger than the sum of its proper divisors (1419854).

2151994 is a wasteful number, since it uses less digits than its factorization.

2151994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2289.

The product of its digits is 3240, while the sum is 31.

The square root of 2151994 is about 1466.9676206379. The cubic root of 2151994 is about 129.1061762314.

It can be divided in two parts, 215 and 1994, that added together give a square (2209 = 47²).

The spelling of 2151994 in words is "two million, one hundred fifty-one thousand, nine hundred ninety-four".