38121990 has 48 divisors (see below), whose sum is σ = 97213392. Its totient is φ = 9565696.

The previous prime is 38121947. The next prime is 38121997. The reversal of 38121990 is 9912183.

It is a super-2 number, since 2×38121990² = 2906572243120200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38121997) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6472 + ... + 10868.

It is an arithmetic number, because the mean of its divisors is an integer number (2025279).

Almost surely, 2^38121990 is an apocalyptic number.

38121990 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 38121990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48606696).

38121990 is an abundant number, since it is smaller than the sum of its proper divisors (59091402).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

38121990 is a wasteful number, since it uses less digits than its factorization.

38121990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4441 (or 4424 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 38121990 is about 6174.3007701277. The cubic root of 38121990 is about 336.5569172489.

The spelling of 38121990 in words is "thirty-eight million, one hundred twenty-one thousand, nine hundred ninety".