73781257 has 4 divisors (see below), whose sum is σ = 80488656. Its totient is φ = 67073860.

The previous prime is 73781243. The next prime is 73781261. The reversal of 73781257 is 75218737.

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.

It is a cyclic number.

It is not a de Polignac number, because 73781257 - 2¹⁵ = 73748489 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (73781287) 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, 3353683 + ... + 3353704.

It is an arithmetic number, because the mean of its divisors is an integer number (20122164).

Almost surely, 2^73781257 is an apocalyptic number.

It is an amenable number.

73781257 is a deficient number, since it is larger than the sum of its proper divisors (6707399).

73781257 is a wasteful number, since it uses less digits than its factorization.

73781257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6707398.

The product of its digits is 82320, while the sum is 40.

The square root of 73781257 is about 8589.6016787742. The cubic root of 73781257 is about 419.4195629109.

The spelling of 73781257 in words is "seventy-three million, seven hundred eighty-one thousand, two hundred fifty-seven".