138998787 has 8 divisors (see below), whose sum is σ = 189275136. Its totient is φ = 90694152.

The previous prime is 138998777. The next prime is 138998791. The reversal of 138998787 is 787899831.

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

It is not a de Polignac number, because 138998787 - 2⁷ = 138998659 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138998787.

It is not an unprimeable number, because it can be changed into a prime (138998777) 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, 492763 + ... + 493044.

It is an arithmetic number, because the mean of its divisors is an integer number (23659392).

Almost surely, 2^138998787 is an apocalyptic number.

138998787 is a deficient number, since it is larger than the sum of its proper divisors (50276349).

138998787 is an equidigital number, since it uses as much as digits as its factorization.

138998787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 985857.

The product of its digits is 6096384, while the sum is 60.

The square root of 138998787 is about 11789.7746797808. The cubic root of 138998787 is about 518.0086399080.

The spelling of 138998787 in words is "one hundred thirty-eight million, nine hundred ninety-eight thousand, seven hundred eighty-seven".