1438217881 has 8 divisors (see below), whose sum is σ = 1462221000. Its totient is φ = 1414406400.

The previous prime is 1438217827. The next prime is 1438217887. The reversal of 1438217881 is 1887128341.

It can be written as a sum of positive squares in 4 ways, for example, as 15721225 + 1422496656 = 3965^2 + 37716^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1438217881 - 2¹¹ = 1438215833 is a prime.

It is a super-2 number, since 2×1438217881² = 4136941346456260322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1438217887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32736 + ... + 62833.

It is an arithmetic number, because the mean of its divisors is an integer number (182777625).

Almost surely, 2^1438217881 is an apocalyptic number.

It is an amenable number.

1438217881 is a deficient number, since it is larger than the sum of its proper divisors (24003119).

1438217881 is a wasteful number, since it uses less digits than its factorization.

1438217881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95819.

The product of its digits is 86016, while the sum is 43.

The square root of 1438217881 is about 37923.8431728642. The cubic root of 1438217881 is about 1128.7771984108. Note that the first 3 decimals are identical.

The spelling of 1438217881 in words is "one billion, four hundred thirty-eight million, two hundred seventeen thousand, eight hundred eighty-one".