73780381 has 2 divisors, whose sum is σ = 73780382. Its totient is φ = 73780380.

The previous prime is 73780367. The next prime is 73780387. The reversal of 73780381 is 18308737.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57304900 + 16475481 = 7570^2 + 4059^2 .

It is an emirp because it is prime and its reverse (18308737) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73780381 - 2⁵ = 73780349 is a prime.

It is a super-2 number, since 2×73780381² = 10887089241010322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 73780381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73780387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36890190 + 36890191.

It is an arithmetic number, because the mean of its divisors is an integer number (36890191).

Almost surely, 2^73780381 is an apocalyptic number.

It is an amenable number.

73780381 is a deficient number, since it is larger than the sum of its proper divisors (1).

73780381 is an equidigital number, since it uses as much as digits as its factorization.

73780381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 73780381 is about 8589.5506867356. The cubic root of 73780381 is about 419.4179029908.

It can be divided in two parts, 737 and 80381, that added together give a palindrome (81118).

The spelling of 73780381 in words is "seventy-three million, seven hundred eighty thousand, three hundred eighty-one".