1903981 has 2 divisors, whose sum is σ = 1903982. Its totient is φ = 1903980.

The previous prime is 1903973. The next prime is 1903987. The reversal of 1903981 is 1893091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1865956 + 38025 = 1366^2 + 195^2 .

It is a cyclic number.

It is not a de Polignac number, because 1903981 - 2³ = 1903973 is a prime.

It is a super-2 number, since 2×1903981² = 7250287296722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1903987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 951990 + 951991.

It is an arithmetic number, because the mean of its divisors is an integer number (951991).

2^1903981 is an apocalyptic number.

It is an amenable number.

1903981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1903981 is an equidigital number, since it uses as much as digits as its factorization.

1903981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 1903981 is about 1379.8481800546. The cubic root of 1903981 is about 123.9426764178.

The spelling of 1903981 in words is "one million, nine hundred three thousand, nine hundred eighty-one".