72000022021 has 4 divisors (see below), whose sum is σ = 76235317452. Its totient is φ = 67764726592.

The previous prime is 72000022009. The next prime is 72000022027. The reversal of 72000022021 is 12022000027.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35218152225 + 36781869796 = 187665^2 + 191786^2 .

It is a cyclic number.

It is not a de Polignac number, because 72000022021 - 2¹⁵ = 71999989253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72000021986 and 72000022004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72000022027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2117647690 + ... + 2117647723.

It is an arithmetic number, because the mean of its divisors is an integer number (19058829363).

Almost surely, 2^72000022021 is an apocalyptic number.

It is an amenable number.

72000022021 is a deficient number, since it is larger than the sum of its proper divisors (4235295431).

72000022021 is a wasteful number, since it uses less digits than its factorization.

72000022021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4235295430.

The product of its (nonzero) digits is 112, while the sum is 16.

Adding to 72000022021 its reverse (12022000027), we get a palindrome (84022022048).

The spelling of 72000022021 in words is "seventy-two billion, twenty-two thousand, twenty-one".