40728791 has 4 divisors (see below), whose sum is σ = 42499632. Its totient is φ = 38957952.

The previous prime is 40728781. The next prime is 40728797. The reversal of 40728791 is 19782704.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 40728791 - 2¹⁴ = 40712407 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 (40728797) 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, 885386 + ... + 885431.

It is an arithmetic number, because the mean of its divisors is an integer number (10624908).

Almost surely, 2^40728791 is an apocalyptic number.

40728791 is a deficient number, since it is larger than the sum of its proper divisors (1770841).

40728791 is a wasteful number, since it uses less digits than its factorization.

40728791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1770840.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 40728791 is about 6381.9112341053. The cubic root of 40728791 is about 344.0597263115.

The spelling of 40728791 in words is "forty million, seven hundred twenty-eight thousand, seven hundred ninety-one".