1438781977 has 4 divisors (see below), whose sum is σ = 1438859556. Its totient is φ = 1438704400.

The previous prime is 1438781947. The next prime is 1438781989. The reversal of 1438781977 is 7791878341.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1234749321 + 204032656 = 35139^2 + 14284^2 .

It is a cyclic number.

It is not a de Polignac number, because 1438781977 - 2¹⁵ = 1438749209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1438781917) 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, 7227 + ... + 54127.

It is an arithmetic number, because the mean of its divisors is an integer number (359714889).

Almost surely, 2^1438781977 is an apocalyptic number.

It is an amenable number.

1438781977 is a deficient number, since it is larger than the sum of its proper divisors (77579).

1438781977 is an equidigital number, since it uses as much as digits as its factorization.

1438781977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77578.

The product of its digits is 2370816, while the sum is 55.

The square root of 1438781977 is about 37931.2796646778. The cubic root of 1438781977 is about 1128.9247549765.

The spelling of 1438781977 in words is "one billion, four hundred thirty-eight million, seven hundred eighty-one thousand, nine hundred seventy-seven".