40252778581 has 4 divisors (see below), whose sum is σ = 40253201964. Its totient is φ = 40252355200.

The previous prime is 40252778557. The next prime is 40252778611. The reversal of 40252778581 is 18587725204.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 8360176356 + 31892602225 = 91434^2 + 178585^2 .

It is a cyclic number.

It is not a de Polignac number, because 40252778581 - 2⁵ = 40252778549 is a prime.

It is a super-2 number, since 2×40252778581² (a number of 22 digits) 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 (40252776581) 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, 4551 + ... + 283771.

It is an arithmetic number, because the mean of its divisors is an integer number (10063300491).

Almost surely, 2^40252778581 is an apocalyptic number.

It is an amenable number.

40252778581 is a deficient number, since it is larger than the sum of its proper divisors (423383).

40252778581 is a wasteful number, since it uses less digits than its factorization.

40252778581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423382.

The product of its (nonzero) digits is 1254400, while the sum is 49.

The spelling of 40252778581 in words is "forty billion, two hundred fifty-two million, seven hundred seventy-eight thousand, five hundred eighty-one".