40138661 has 2 divisors, whose sum is σ = 40138662. Its totient is φ = 40138660.

The previous prime is 40138607. The next prime is 40138687. The reversal of 40138661 is 16683104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22033636 + 18105025 = 4694^2 + 4255^2 .

It is a cyclic number.

It is not a de Polignac number, because 40138661 - 2⁶ = 40138597 is a prime.

It is a super-2 number, since 2×40138661² = 3222224213745842, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40138601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20069330 + 20069331.

It is an arithmetic number, because the mean of its divisors is an integer number (20069331).

Almost surely, 2^40138661 is an apocalyptic number.

It is an amenable number.

40138661 is a deficient number, since it is larger than the sum of its proper divisors (1).

40138661 is an equidigital number, since it uses as much as digits as its factorization.

40138661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 40138661 is about 6335.5079512222. The cubic root of 40138661 is about 342.3899118721.

The spelling of 40138661 in words is "forty million, one hundred thirty-eight thousand, six hundred sixty-one".