40203661 has 4 divisors (see below), whose sum is σ = 40292092. Its totient is φ = 40115232.

The previous prime is 40203641. The next prime is 40203673. The reversal of 40203661 is 16630204.

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 18404100 + 21799561 = 4290^2 + 4669^2 .

It is a cyclic number.

It is not a de Polignac number, because 40203661 - 2¹⁷ = 40072589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40203641) 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, 43530 + ... + 44443.

It is an arithmetic number, because the mean of its divisors is an integer number (10073023).

Almost surely, 2^40203661 is an apocalyptic number.

It is an amenable number.

40203661 is a deficient number, since it is larger than the sum of its proper divisors (88431).

40203661 is an equidigital number, since it uses as much as digits as its factorization.

40203661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88430.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 40203661 is about 6340.6356936825. The cubic root of 40203661 is about 342.5746327138.

Adding to 40203661 its reverse (16630204), we get a palindrome (56833865).

The spelling of 40203661 in words is "forty million, two hundred three thousand, six hundred sixty-one".