72435821 has 2 divisors, whose sum is σ = 72435822. Its totient is φ = 72435820.

The previous prime is 72435787. The next prime is 72435859. The reversal of 72435821 is 12853427.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57912100 + 14523721 = 7610^2 + 3811^2 .

It is a cyclic number.

It is not a de Polignac number, because 72435821 - 2¹⁸ = 72173677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72435221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36217910 + 36217911.

It is an arithmetic number, because the mean of its divisors is an integer number (36217911).

Almost surely, 2^72435821 is an apocalyptic number.

It is an amenable number.

72435821 is a deficient number, since it is larger than the sum of its proper divisors (1).

72435821 is an equidigital number, since it uses as much as digits as its factorization.

72435821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 32.

The square root of 72435821 is about 8510.9236279031. The cubic root of 72435821 is about 416.8544694373.

The spelling of 72435821 in words is "seventy-two million, four hundred thirty-five thousand, eight hundred twenty-one".