1630981 has 8 divisors (see below), whose sum is σ = 1806624. Its totient is φ = 1459920.

The previous prime is 1630943. The next prime is 1630987. The reversal of 1630981 is 1890361.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1630981 - 2¹¹ = 1628933 is a prime.

It is a super-2 number, since 2×1630981² = 5320198044722, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1630987) 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, 370 + ... + 1843.

It is an arithmetic number, because the mean of its divisors is an integer number (225828).

2^1630981 is an apocalyptic number.

1630981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1630981 is a deficient number, since it is larger than the sum of its proper divisors (175643).

1630981 is a wasteful number, since it uses less digits than its factorization.

1630981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2291.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 1630981 is about 1277.0986649433. The cubic root of 1630981 is about 117.7107970943.

The spelling of 1630981 in words is "one million, six hundred thirty thousand, nine hundred eighty-one".