1394999991 has 48 divisors (see below), whose sum is σ = 2660007168. Its totient is φ = 682041600.

The previous prime is 1394999989. The next prime is 1394999993. The reversal of 1394999991 is 1999994931.

1394999991 is a `hidden beast` number, since 139 + 499 + 9 + 9 + 9 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1394999989) and next prime (1394999993).

It is not a de Polignac number, because 1394999991 - 2¹ = 1394999989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1394999993) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 47425 + ... + 70986.

It is an arithmetic number, because the mean of its divisors is an integer number (55416816).

Almost surely, 2^1394999991 is an apocalyptic number.

1394999991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1394999991 is a deficient number, since it is larger than the sum of its proper divisors (1265007177).

1394999991 is a wasteful number, since it uses less digits than its factorization.

1394999991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118452 (or 118449 counting only the distinct ones).

The product of its digits is 6377292, while the sum is 63.

The square root of 1394999991 is about 37349.6986734833. The cubic root of 1394999991 is about 1117.3555785316.

The spelling of 1394999991 in words is "one billion, three hundred ninety-four million, nine hundred ninety-nine thousand, nine hundred ninety-one".