73387781 has 2 divisors, whose sum is σ = 73387782. Its totient is φ = 73387780.

The previous prime is 73387771. The next prime is 73387807. The reversal of 73387781 is 18778337.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71402500 + 1985281 = 8450^2 + 1409^2 .

It is a cyclic number.

It is not a de Polignac number, because 73387781 - 2²² = 69193477 is a prime.

It is a super-2 number, since 2×73387781² = 10771532800207922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73387751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36693890 + 36693891.

It is an arithmetic number, because the mean of its divisors is an integer number (36693891).

Almost surely, 2^73387781 is an apocalyptic number.

It is an amenable number.

73387781 is a deficient number, since it is larger than the sum of its proper divisors (1).

73387781 is an equidigital number, since it uses as much as digits as its factorization.

73387781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 197568, while the sum is 44.

The square root of 73387781 is about 8566.6668547341. Note that the first 3 decimals coincide. The cubic root of 73387781 is about 418.6726443283.

The spelling of 73387781 in words is "seventy-three million, three hundred eighty-seven thousand, seven hundred eighty-one".