1387090731 has 8 divisors (see below), whose sum is σ = 1991720080. Its totient is φ = 853594272.

The previous prime is 1387090729. The next prime is 1387090751. The reversal of 1387090731 is 1370907831.

It is a happy number.

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

It is not a de Polignac number, because 1387090731 - 2¹ = 1387090729 is a prime.

It is a super-2 number, since 2×1387090731² = 3848041392052228722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 35566429 = 1387090731 / (1 + 3 + 8 + 7 + 0 + 9 + 0 + 7 + 3 + 1).

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 1387090731.

It is not an unprimeable number, because it can be changed into a prime (1387090711) 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, 17783176 + ... + 17783253.

It is an arithmetic number, because the mean of its divisors is an integer number (248965010).

Almost surely, 2^1387090731 is an apocalyptic number.

1387090731 is a deficient number, since it is larger than the sum of its proper divisors (604629349).

1387090731 is a wasteful number, since it uses less digits than its factorization.

1387090731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35566445.

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 1387090731 is about 37243.6669918525. Note that the first 3 decimals coincide. The cubic root of 1387090731 is about 1115.2398770701.

The spelling of 1387090731 in words is "one billion, three hundred eighty-seven million, ninety thousand, seven hundred thirty-one".