38478721 has 2 divisors, whose sum is σ = 38478722. Its totient is φ = 38478720.

The previous prime is 38478707. The next prime is 38478731. The reversal of 38478721 is 12787483.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32890225 + 5588496 = 5735^2 + 2364^2 .

It is a cyclic number.

It is not a de Polignac number, because 38478721 - 2¹⁷ = 38347649 is a prime.

It is a super-2 number, since 2×38478721² = 2961223939591682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (38478731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19239360 + 19239361.

It is an arithmetic number, because the mean of its divisors is an integer number (19239361).

Almost surely, 2^38478721 is an apocalyptic number.

It is an amenable number.

38478721 is a deficient number, since it is larger than the sum of its proper divisors (1).

38478721 is an equidigital number, since it uses as much as digits as its factorization.

38478721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 40.

The square root of 38478721 is about 6203.1218753141. The cubic root of 38478721 is about 337.6034499518.

The spelling of 38478721 in words is "thirty-eight million, four hundred seventy-eight thousand, seven hundred twenty-one".