40405997 has 4 divisors (see below), whose sum is σ = 40435296. Its totient is φ = 40376700.

The previous prime is 40405993. The next prime is 40406081. The reversal of 40405997 is 79950404.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40405997 - 2² = 40405993 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40405997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40405993) 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, 12473 + ... + 15374.

It is an arithmetic number, because the mean of its divisors is an integer number (10108824).

Almost surely, 2^40405997 is an apocalyptic number.

It is an amenable number.

40405997 is a deficient number, since it is larger than the sum of its proper divisors (29299).

40405997 is a wasteful number, since it uses less digits than its factorization.

40405997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29298.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 40405997 is about 6356.5711669107. The cubic root of 40405997 is about 343.1483716937.

The spelling of 40405997 in words is "forty million, four hundred five thousand, nine hundred ninety-seven".