40388749 has 4 divisors (see below), whose sum is σ = 40449436. Its totient is φ = 40328064.

The previous prime is 40388729. The next prime is 40388767. The reversal of 40388749 is 94788304.

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 22155849 + 18232900 = 4707^2 + 4270^2 .

It is a cyclic number.

It is not a de Polignac number, because 40388749 - 2¹¹ = 40386701 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 (40388729) 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, 29334 + ... + 30679.

It is an arithmetic number, because the mean of its divisors is an integer number (10112359).

Almost surely, 2^40388749 is an apocalyptic number.

It is an amenable number.

40388749 is a deficient number, since it is larger than the sum of its proper divisors (60687).

40388749 is an equidigital number, since it uses as much as digits as its factorization.

40388749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60686.

The product of its (nonzero) digits is 193536, while the sum is 43.

The square root of 40388749 is about 6355.2143158197. The cubic root of 40388749 is about 343.0995384683.

The spelling of 40388749 in words is "forty million, three hundred eighty-eight thousand, seven hundred forty-nine".