40187135981 has 4 divisors (see below), whose sum is σ = 40202636892. Its totient is φ = 40171635072.

The previous prime is 40187135957. The next prime is 40187136029. The reversal of 40187135981 is 18953178104.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21978062500 + 18209073481 = 148250^2 + 134941^2 .

It is a cyclic number.

It is not a de Polignac number, because 40187135981 - 2¹⁰ = 40187134957 is a prime.

It is a super-2 number, since 2×40187135981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40187935981) 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, 7746566 + ... + 7751751.

It is an arithmetic number, because the mean of its divisors is an integer number (10050659223).

Almost surely, 2^40187135981 is an apocalyptic number.

It is an amenable number.

40187135981 is a deficient number, since it is larger than the sum of its proper divisors (15500911).

40187135981 is a wasteful number, since it uses less digits than its factorization.

40187135981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15500910.

The product of its (nonzero) digits is 241920, while the sum is 47.

The spelling of 40187135981 in words is "forty billion, one hundred eighty-seven million, one hundred thirty-five thousand, nine hundred eighty-one".