40071721 has 8 divisors (see below), whose sum is σ = 40749984. Its totient is φ = 39399360.

The previous prime is 40071701. The next prime is 40071749. The reversal of 40071721 is 12717004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40071721 - 2⁷ = 40071593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40071692 and 40071701.

It is not an unprimeable number, because it can be changed into a prime (40071701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13450 + ... + 16156.

It is an arithmetic number, because the mean of its divisors is an integer number (5093748).

Almost surely, 2^40071721 is an apocalyptic number.

It is an amenable number.

40071721 is a deficient number, since it is larger than the sum of its proper divisors (678263).

40071721 is a wasteful number, since it uses less digits than its factorization.

40071721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2951.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 40071721 is about 6330.2228238823. Note that the first 3 decimals coincide. The cubic root of 40071721 is about 342.1994692657.

Adding to 40071721 its reverse (12717004), we get a palindrome (52788725).

The spelling of 40071721 in words is "forty million, seventy-one thousand, seven hundred twenty-one".