38723821 has 2 divisors, whose sum is σ = 38723822. Its totient is φ = 38723820.

The previous prime is 38723791. The next prime is 38723831. The reversal of 38723821 is 12832783.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36735721 + 1988100 = 6061^2 + 1410^2 .

It is a cyclic number.

It is not a de Polignac number, because 38723821 - 2¹¹ = 38721773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38723831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19361910 + 19361911.

It is an arithmetic number, because the mean of its divisors is an integer number (19361911).

Almost surely, 2^38723821 is an apocalyptic number.

It is an amenable number.

38723821 is a deficient number, since it is larger than the sum of its proper divisors (1).

38723821 is an equidigital number, since it uses as much as digits as its factorization.

38723821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 34.

The square root of 38723821 is about 6222.8466958459. The cubic root of 38723821 is about 338.3187503455.

The spelling of 38723821 in words is "thirty-eight million, seven hundred twenty-three thousand, eight hundred twenty-one".