1981351 has 4 divisors (see below), whose sum is σ = 1992600. Its totient is φ = 1970104.

The previous prime is 1981349. The next prime is 1981361. The reversal of 1981351 is 1531891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1531891 = 167 ⋅9173.

It is a cyclic number.

It is not a de Polignac number, because 1981351 - 2¹ = 1981349 is a prime.

It is a super-3 number, since 3×1981351³ = 23334876676079359653, which contains 333 as substring.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981361) 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, 5356 + ... + 5713.

It is an arithmetic number, because the mean of its divisors is an integer number (498150).

2^1981351 is an apocalyptic number.

1981351 is the 630-th centered decagonal number.

1981351 is a deficient number, since it is larger than the sum of its proper divisors (11249).

1981351 is a wasteful number, since it uses less digits than its factorization.

1981351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11248.

The product of its digits is 1080, while the sum is 28.

The square root of 1981351 is about 1407.6047030328. The cubic root of 1981351 is about 125.5992770118.

It can be divided in two parts, 1981 and 351, that added together give a palindrome (2332).

The spelling of 1981351 in words is "one million, nine hundred eighty-one thousand, three hundred fifty-one".