40401721 has 4 divisors (see below), whose sum is σ = 40432000. Its totient is φ = 40371444.

The previous prime is 40401719. The next prime is 40401749. The reversal of 40401721 is 12710404.

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 40401721 - 2¹ = 40401719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40401701) 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, 13041 + ... + 15838.

It is an arithmetic number, because the mean of its divisors is an integer number (10108000).

Almost surely, 2^40401721 is an apocalyptic number.

It is an amenable number.

40401721 is a deficient number, since it is larger than the sum of its proper divisors (30279).

40401721 is a wasteful number, since it uses less digits than its factorization.

40401721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30278.

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 40401721 is about 6356.2348131579. The cubic root of 40401721 is about 343.1362666077.

The spelling of 40401721 in words is "forty million, four hundred one thousand, seven hundred twenty-one".