72681442 has 4 divisors (see below), whose sum is σ = 109022166. Its totient is φ = 36340720.

The previous prime is 72681437. The next prime is 72681463. The reversal of 72681442 is 24418627.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24418627 = 547 ⋅44641.

It can be written as a sum of positive squares in only one way, i.e., 64947481 + 7733961 = 8059^2 + 2781^2 .

It is a super-2 number, since 2×72681442² = 10565184022398728, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72681398 and 72681407.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18170359 + ... + 18170362.

Almost surely, 2^72681442 is an apocalyptic number.

72681442 is a deficient number, since it is larger than the sum of its proper divisors (36340724).

72681442 is a wasteful number, since it uses less digits than its factorization.

72681442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36340723.

The product of its digits is 21504, while the sum is 34.

The square root of 72681442 is about 8525.3411661939. The cubic root of 72681442 is about 417.3251053700.

The spelling of 72681442 in words is "seventy-two million, six hundred eighty-one thousand, four hundred forty-two".