921378780 has 192 divisors, whose sum is σ = 3448704000. Its totient is φ = 199501056.

The previous prime is 921378779. The next prime is 921378791. The reversal of 921378780 is 87873129.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 65406 + ... + 78234.

It is an arithmetic number, because the mean of its divisors is an integer number (17962000).

Almost surely, 2^921378780 is an apocalyptic number.

921378780 is a gapful number since it is divisible by the number (90) 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 921378780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1724352000).

921378780 is an abundant number, since it is smaller than the sum of its proper divisors (2527325220).

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

921378780 is a wasteful number, since it uses less digits than its factorization.

921378780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12873 (or 12865 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 921378780 is about 30354.2217821508. The cubic root of 921378780 is about 973.0744482039.

The spelling of 921378780 in words is "nine hundred twenty-one million, three hundred seventy-eight thousand, seven hundred eighty".