1905741981 has 48 divisors (see below), whose sum is σ = 3374646912. Its totient is φ = 1019779200.

The previous prime is 1905741979. The next prime is 1905741991. The reversal of 1905741981 is 1891475091.

It is a happy number.

It is not a de Polignac number, because 1905741981 - 2¹ = 1905741979 is a prime.

It is a super-2 number, since 2×1905741981² = 7263704996291608722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1905741911) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2590 + ... + 61791.

It is an arithmetic number, because the mean of its divisors is an integer number (70305144).

Almost surely, 2^1905741981 is an apocalyptic number.

1905741981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1905741981 is a deficient number, since it is larger than the sum of its proper divisors (1468904931).

1905741981 is a wasteful number, since it uses less digits than its factorization.

1905741981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64434 (or 64431 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 45.

The square root of 1905741981 is about 43654.8047871022. The cubic root of 1905741981 is about 1239.8087593122.

The spelling of 1905741981 in words is "one billion, nine hundred five million, seven hundred forty-one thousand, nine hundred eighty-one".