40721231 has 4 divisors (see below), whose sum is σ = 40734000. Its totient is φ = 40708464.

The previous prime is 40721209. The next prime is 40721243. The reversal of 40721231 is 13212704.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 40721231 - 2⁶ = 40721167 is a prime.

It is a super-2 number, since 2×40721231² = 3316437308310722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40721251) 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, 2915 + ... + 9483.

It is an arithmetic number, because the mean of its divisors is an integer number (10183500).

Almost surely, 2^40721231 is an apocalyptic number.

40721231 is a deficient number, since it is larger than the sum of its proper divisors (12769).

40721231 is an equidigital number, since it uses as much as digits as its factorization.

40721231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12768.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 40721231 is about 6381.3189075614. The cubic root of 40721231 is about 344.0384370923.

Adding to 40721231 its reverse (13212704), we get a palindrome (53933935).

The spelling of 40721231 in words is "forty million, seven hundred twenty-one thousand, two hundred thirty-one".