40491551 has 4 divisors (see below), whose sum is σ = 40668600. Its totient is φ = 40314504.

The previous prime is 40491547. The next prime is 40491553. The reversal of 40491551 is 15519404.

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

It is a cyclic number.

It is not a de Polignac number, because 40491551 - 2² = 40491547 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 (40491553) 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, 88181 + ... + 88638.

It is an arithmetic number, because the mean of its divisors is an integer number (10167150).

Almost surely, 2^40491551 is an apocalyptic number.

40491551 is a deficient number, since it is larger than the sum of its proper divisors (177049).

40491551 is a wasteful number, since it uses less digits than its factorization.

40491551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177048.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 40491551 is about 6363.2971799217. The cubic root of 40491551 is about 343.3903903875.

The spelling of 40491551 in words is "forty million, four hundred ninety-one thousand, five hundred fifty-one".