1921425408 has 448 divisors, whose sum is σ = 6983089920. Its totient is φ = 509607936.

The previous prime is 1921425371. The next prime is 1921425409. The reversal of 1921425408 is 8045241291.

1921425408 is a `hidden beast` number, since 19 + 214 + 25 + 408 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921425409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26320860 + ... + 26320932.

Almost surely, 2^1921425408 is an apocalyptic number.

1921425408 is a gapful number since it is divisible by the number (18) 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 1921425408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3491544960).

1921425408 is an abundant number, since it is smaller than the sum of its proper divisors (5061664512).

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

1921425408 is an equidigital number, since it uses as much as digits as its factorization.

1921425408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 1921425408 is about 43834.0667517856. The cubic root of 1921425408 is about 1243.2005008868.

Adding to 1921425408 its reverse (8045241291), we get a palindrome (9966666699).

The spelling of 1921425408 in words is "one billion, nine hundred twenty-one million, four hundred twenty-five thousand, four hundred eight".