1387921723 has 4 divisors (see below), whose sum is σ = 1411445880. Its totient is φ = 1364397568.

The previous prime is 1387921721. The next prime is 1387921741. The reversal of 1387921723 is 3271297831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1387921723 - 2¹ = 1387921721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1387921723.

It is not an unprimeable number, because it can be changed into a prime (1387921721) 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, 11761990 + ... + 11762107.

It is an arithmetic number, because the mean of its divisors is an integer number (352861470).

Almost surely, 2^1387921723 is an apocalyptic number.

1387921723 is a deficient number, since it is larger than the sum of its proper divisors (23524157).

1387921723 is an equidigital number, since it uses as much as digits as its factorization.

1387921723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23524156.

The product of its digits is 127008, while the sum is 43.

The square root of 1387921723 is about 37254.8214731999. The cubic root of 1387921723 is about 1115.4625422467.

The spelling of 1387921723 in words is "one billion, three hundred eighty-seven million, nine hundred twenty-one thousand, seven hundred twenty-three".