1955981 has 4 divisors (see below), whose sum is σ = 1961472. Its totient is φ = 1950492.

The previous prime is 1955977. The next prime is 1955983. The reversal of 1955981 is 1895591.

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 1955981 - 2² = 1955977 is a prime.

It is a super-2 number, since 2×1955981² = 7651723344722, 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 (1955983) 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, 2171 + ... + 2936.

It is an arithmetic number, because the mean of its divisors is an integer number (490368).

2^1955981 is an apocalyptic number.

It is an amenable number.

1955981 is a deficient number, since it is larger than the sum of its proper divisors (5491).

1955981 is an equidigital number, since it uses as much as digits as its factorization.

1955981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5490.

The product of its digits is 16200, while the sum is 38.

The square root of 1955981 is about 1398.5639062982. The cubic root of 1955981 is about 125.0608983263.

The spelling of 1955981 in words is "one million, nine hundred fifty-five thousand, nine hundred eighty-one".