72187789 has 4 divisors (see below), whose sum is σ = 72205056. Its totient is φ = 72170524.

The previous prime is 72187781. The next prime is 72187793. The reversal of 72187789 is 98778127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98778127 = 7 ⋅14111161.

It is a cyclic number.

It is not a de Polignac number, because 72187789 - 2³ = 72187781 is a prime.

It is a super-2 number, since 2×72187789² = 10422153761417042, 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 (72187781) 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, 2022 + ... + 12184.

It is an arithmetic number, because the mean of its divisors is an integer number (18051264).

Almost surely, 2^72187789 is an apocalyptic number.

It is an amenable number.

72187789 is a deficient number, since it is larger than the sum of its proper divisors (17267).

72187789 is a wasteful number, since it uses less digits than its factorization.

72187789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17266.

The product of its digits is 395136, while the sum is 49.

The square root of 72187789 is about 8496.3397413239. The cubic root of 72187789 is about 416.3781328997.

The spelling of 72187789 in words is "seventy-two million, one hundred eighty-seven thousand, seven hundred eighty-nine".