1391445620 has 54 divisors (see below), whose sum is σ = 3090962322. Its totient is φ = 526083552.

The previous prime is 1391445617. The next prime is 1391445637. The reversal of 1391445620 is 265441931.

It can be written as a sum of positive squares in only one way, i.e., 1113156496 + 278289124 = 33364^2 + 16682^2 .

It is a super-2 number, since 2×1391445620² = 3872241826834368800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3169361 + ... + 3169799.

It is an arithmetic number, because the mean of its divisors is an integer number (57240043).

Almost surely, 2^1391445620 is an apocalyptic number.

1391445620 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 1391445620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1545481161).

1391445620 is an abundant number, since it is smaller than the sum of its proper divisors (1699516702).

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

1391445620 is an equidigital number, since it uses as much as digits as its factorization.

1391445620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 925 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 1391445620 is about 37302.0860006515. The cubic root of 1391445620 is about 1116.4057878236.

Multiplying 1391445620 by its product of nonzero digits (25920), we get a square (36066270470400 = 6005520²).

The spelling of 1391445620 in words is "one billion, three hundred ninety-one million, four hundred forty-five thousand, six hundred twenty".