1391889520 has 80 divisors (see below), whose sum is σ = 3727761408. Its totient is φ = 473437440.

The previous prime is 1391889497. The next prime is 1391889529. The reversal of 1391889520 is 259881931.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1391889529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61335 + ... + 80905.

Almost surely, 2^1391889520 is an apocalyptic number.

1391889520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1391889520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1863880704).

1391889520 is an abundant number, since it is smaller than the sum of its proper divisors (2335871888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1391889520 is a wasteful number, since it uses less digits than its factorization.

1391889520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19718 (or 19712 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 1391889520 is about 37308.0355955657. The cubic root of 1391889520 is about 1116.5244940651.

The spelling of 1391889520 in words is "one billion, three hundred ninety-one million, eight hundred eighty-nine thousand, five hundred twenty".