2151431 has 4 divisors (see below), whose sum is σ = 2220864. Its totient is φ = 2082000.

The previous prime is 2151421. The next prime is 2151433. The reversal of 2151431 is 1341512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2151431 - 2¹⁸ = 1889287 is a prime.

It is a super-2 number, since 2×2151431² = 9257310695522, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151433) 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, 34670 + ... + 34731.

It is an arithmetic number, because the mean of its divisors is an integer number (555216).

2^2151431 is an apocalyptic number.

2151431 is a deficient number, since it is larger than the sum of its proper divisors (69433).

2151431 is an equidigital number, since it uses as much as digits as its factorization.

2151431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69432.

The product of its digits is 120, while the sum is 17.

The square root of 2151431 is about 1466.7757156430. The cubic root of 2151431 is about 129.0949164235.

Adding to 2151431 its reverse (1341512), we get a palindrome (3492943).

The spelling of 2151431 in words is "two million, one hundred fifty-one thousand, four hundred thirty-one".