1387546991 has 8 divisors (see below), whose sum is σ = 1460943600. Its totient is φ = 1314187200.

The previous prime is 1387546973. The next prime is 1387546997. The reversal of 1387546991 is 1996457831.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1387546991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387546997) 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, 103925 + ... + 116513.

It is an arithmetic number, because the mean of its divisors is an integer number (182617950).

Almost surely, 2^1387546991 is an apocalyptic number.

1387546991 is a deficient number, since it is larger than the sum of its proper divisors (73396609).

1387546991 is a wasteful number, since it uses less digits than its factorization.

1387546991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18409.

The product of its digits is 1632960, while the sum is 53.

The square root of 1387546991 is about 37249.7918249217. The cubic root of 1387546991 is about 1115.3621434208.

The spelling of 1387546991 in words is "one billion, three hundred eighty-seven million, five hundred forty-six thousand, nine hundred ninety-one".