2151969 has 4 divisors (see below), whose sum is σ = 2869296. Its totient is φ = 1434644.

The previous prime is 2151943. The next prime is 2151971. The reversal of 2151969 is 9691512.

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 a cyclic number.

It is not a de Polignac number, because 2151969 - 2¹⁶ = 2086433 is a prime.

It is a super-2 number, since 2×2151969² = 9261941153922, which contains 22 as substring.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (2151269) 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, 358659 + ... + 358664.

It is an arithmetic number, because the mean of its divisors is an integer number (717324).

2^2151969 is an apocalyptic number.

It is an amenable number.

2151969 is a deficient number, since it is larger than the sum of its proper divisors (717327).

2151969 is an equidigital number, since it uses as much as digits as its factorization.

2151969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717326.

The product of its digits is 4860, while the sum is 33.

The square root of 2151969 is about 1466.9590996343. The cubic root of 2151969 is about 129.1056762816.

The spelling of 2151969 in words is "two million, one hundred fifty-one thousand, nine hundred sixty-nine".