1945681920 has 720 divisors, whose sum is σ = 8587575360. Its totient is φ = 396361728.

The previous prime is 1945681919. The next prime is 1945681951. The reversal of 1945681920 is 291865491.

1945681920 is a `hidden beast` number, since 1 + 9 + 456 + 8 + 192 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 67092466 + ... + 67092494.

It is an arithmetic number, because the mean of its divisors is an integer number (11927188).

Almost surely, 2^1945681920 is an apocalyptic number.

1945681920 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 1945681920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4293787680).

1945681920 is an abundant number, since it is smaller than the sum of its proper divisors (6641893440).

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

1945681920 is a wasteful number, since it uses less digits than its factorization.

1945681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 1945681920 is about 44109.8846065142. The cubic root of 1945681920 is about 1248.4101216201.

It can be divided in two parts, 1945 and 681920, that added together give a triangular number (683865 = T₁₁₆₉).

The spelling of 1945681920 in words is "one billion, nine hundred forty-five million, six hundred eighty-one thousand, nine hundred twenty".