9400400721 has 12 divisors (see below), whose sum is σ = 14046576180. Its totient is φ = 6050832480.

The previous prime is 9400400719. The next prime is 9400400741. The reversal of 9400400721 is 1270040049.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4520679696 + 4879721025 = 67236^2 + 69855^2 .

It is not a de Polignac number, because 9400400721 - 2¹ = 9400400719 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9400400701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18008170 + ... + 18008691.

It is an arithmetic number, because the mean of its divisors is an integer number (1170548015).

Almost surely, 2^9400400721 is an apocalyptic number.

It is an amenable number.

9400400721 is a deficient number, since it is larger than the sum of its proper divisors (4646175459).

9400400721 is a wasteful number, since it uses less digits than its factorization.

9400400721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36016896 (or 36016893 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 9400400721 is about 96955.6636870688. The cubic root of 9400400721 is about 2110.4842835447.

The spelling of 9400400721 in words is "nine billion, four hundred million, four hundred thousand, seven hundred twenty-one".