38400021 has 16 divisors (see below), whose sum is σ = 62061120. Its totient is φ = 23272560.

The previous prime is 38399983. The next prime is 38400023. The reversal of 38400021 is 12000483.

It is a happy number.

It is not a de Polignac number, because 38400021 - 2¹¹ = 38397973 is a prime.

It is a super-2 number, since 2×38400021² = 2949123225600882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 38399967 and 38400003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38400023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64350 + ... + 64943.

It is an arithmetic number, because the mean of its divisors is an integer number (3878820).

Almost surely, 2^38400021 is an apocalyptic number.

It is an amenable number.

38400021 is a deficient number, since it is larger than the sum of its proper divisors (23661099).

38400021 is a wasteful number, since it uses less digits than its factorization.

38400021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129313 (or 129307 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 38400021 is about 6196.7750483618. The cubic root of 38400021 is about 337.3731276210.

The spelling of 38400021 in words is "thirty-eight million, four hundred thousand, twenty-one".