196405981 has 4 divisors (see below), whose sum is σ = 207959292. Its totient is φ = 184852672.

The previous prime is 196405973. The next prime is 196405991. The reversal of 196405981 is 189504691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 189504691 = 9677 ⋅19583.

It can be written as a sum of positive squares in 2 ways, for example, as 182493081 + 13912900 = 13509^2 + 3730^2 .

It is a cyclic number.

It is not a de Polignac number, because 196405981 - 2³ = 196405973 is a prime.

It is a super-2 number, since 2×196405981² = 77150618745144722, 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 (196405991) 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, 5776630 + ... + 5776663.

It is an arithmetic number, because the mean of its divisors is an integer number (51989823).

Almost surely, 2^196405981 is an apocalyptic number.

It is an amenable number.

196405981 is a deficient number, since it is larger than the sum of its proper divisors (11553311).

196405981 is a wasteful number, since it uses less digits than its factorization.

196405981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11553310.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 196405981 is about 14014.4918209688. The cubic root of 196405981 is about 581.2793608169.

The spelling of 196405981 in words is "one hundred ninety-six million, four hundred five thousand, nine hundred eighty-one".