72405955546 has 4 divisors (see below), whose sum is σ = 108608933322. Its totient is φ = 36202977772.

The previous prime is 72405955513. The next prime is 72405955547. The reversal of 72405955546 is 64555950427.

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: 64555950427 = 601 ⋅107414227.

It can be written as a sum of positive squares in only one way, i.e., 52619313321 + 19786642225 = 229389^2 + 140665^2 .

It is a junction number, because it is equal to n+sod(n) for n = 72405955493 and 72405955502.

It is not an unprimeable number, because it can be changed into a prime (72405955547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18101488885 + ... + 18101488888.

Almost surely, 2^72405955546 is an apocalyptic number.

72405955546 is a deficient number, since it is larger than the sum of its proper divisors (36202977776).

72405955546 is a wasteful number, since it uses less digits than its factorization.

72405955546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36202977775.

The product of its (nonzero) digits is 7560000, while the sum is 52.

The spelling of 72405955546 in words is "seventy-two billion, four hundred five million, nine hundred fifty-five thousand, five hundred forty-six".