40387661 has 4 divisors (see below), whose sum is σ = 40758300. Its totient is φ = 40017024.

The previous prime is 40387649. The next prime is 40387663. The reversal of 40387661 is 16678304.

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 21949225 + 18438436 = 4685^2 + 4294^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40387661 is a prime.

It is a super-2 number, since 2×40387661² = 3262326322101842, which 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 (40387663) 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, 185156 + ... + 185373.

It is an arithmetic number, because the mean of its divisors is an integer number (10189575).

Almost surely, 2^40387661 is an apocalyptic number.

It is an amenable number.

40387661 is a deficient number, since it is larger than the sum of its proper divisors (370639).

40387661 is a wasteful number, since it uses less digits than its factorization.

40387661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370638.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 40387661 is about 6355.1287162417. The cubic root of 40387661 is about 343.0964576132.

The spelling of 40387661 in words is "forty million, three hundred eighty-seven thousand, six hundred sixty-one".