1642981 has 4 divisors (see below), whose sum is σ = 1652652. Its totient is φ = 1633312.

The previous prime is 1642951. The next prime is 1642997. The reversal of 1642981 is 1892461.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 749956 + 893025 = 866^2 + 945^2 .

It is a cyclic number.

It is not a de Polignac number, because 1642981 - 2⁷ = 1642853 is a prime.

It is a super-2 number, since 2×1642981² = 5398773132722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642951) 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, 4576 + ... + 4921.

It is an arithmetic number, because the mean of its divisors is an integer number (413163).

2^1642981 is an apocalyptic number.

It is an amenable number.

1642981 is a deficient number, since it is larger than the sum of its proper divisors (9671).

1642981 is an equidigital number, since it uses as much as digits as its factorization.

1642981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9670.

The product of its digits is 3456, while the sum is 31.

The square root of 1642981 is about 1281.7882040337. The cubic root of 1642981 is about 117.9987790738.

It can be divided in two parts, 164 and 2981, that multiplied together give a palindrome (488884).

The spelling of 1642981 in words is "one million, six hundred forty-two thousand, nine hundred eighty-one".