1983900681 has 75 divisors (see below), whose sum is σ = 3491903063. Its totient is φ = 1122433200.

The previous prime is 1983900649. The next prime is 1983900727. The reversal of 1983900681 is 1860093891.

The square root of 1983900681 is 44541.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1906108281 + 77792400 = 43659^2 + 8820^2 .

It is not a de Polignac number, because 1983900681 - 2⁵ = 1983900649 is a prime.

It is a super-2 number, since 2×1983900681² = 7871723824144527522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1983900601) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 19642531 + ... + 19642631.

Almost surely, 2^1983900681 is an apocalyptic number.

1983900681 is the 44541-st square number.

1983900681 is the 22271-st centered octagonal number.

It is an amenable number.

1983900681 is a deficient number, since it is larger than the sum of its proper divisors (1508002382).

1983900681 is an frugal number, since it uses more digits than its factorization.

1983900681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The cubic root of 1983900681 is about 1256.5312929464.

The spelling of 1983900681 in words is "one billion, nine hundred eighty-three million, nine hundred thousand, six hundred eighty-one".