38778421 has 4 divisors (see below), whose sum is σ = 42303744. Its totient is φ = 35253100.

The previous prime is 38778419. The next prime is 38778433. The reversal of 38778421 is 12487783.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 38778421 - 2¹ = 38778419 is a prime.

It is a super-3 number, since 3×38778421³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38778401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1762645 + ... + 1762666.

It is an arithmetic number, because the mean of its divisors is an integer number (10575936).

Almost surely, 2^38778421 is an apocalyptic number.

It is an amenable number.

38778421 is a deficient number, since it is larger than the sum of its proper divisors (3525323).

38778421 is a wasteful number, since it uses less digits than its factorization.

38778421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3525322.

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

The square root of 38778421 is about 6227.2322102199. The cubic root of 38778421 is about 338.4776837724.

The spelling of 38778421 in words is "thirty-eight million, seven hundred seventy-eight thousand, four hundred twenty-one".