1620778378 has 8 divisors (see below), whose sum is σ = 2461942080. Its totient is φ = 800131020.

The previous prime is 1620778373. The next prime is 1620778381. The reversal of 1620778378 is 8738770261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1620778373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5128888 + ... + 5129203.

It is an arithmetic number, because the mean of its divisors is an integer number (307742760).

Almost surely, 2^1620778378 is an apocalyptic number.

1620778378 is a deficient number, since it is larger than the sum of its proper divisors (841163702).

1620778378 is a wasteful number, since it uses less digits than its factorization.

1620778378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10258172.

The product of its (nonzero) digits is 790272, while the sum is 49.

The square root of 1620778378 is about 40258.8919122223. The cubic root of 1620778378 is about 1174.6483638894.

The spelling of 1620778378 in words is "one billion, six hundred twenty million, seven hundred seventy-eight thousand, three hundred seventy-eight".