1378523820 has 24 divisors (see below), whose sum is σ = 3859866864. Its totient is φ = 367606336.

The previous prime is 1378523803. The next prime is 1378523821. The reversal of 1378523820 is 283258731.

It is a super-4 number, since 4×1378523820⁴ (a number of 38 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (1378523821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11487639 + ... + 11487758.

It is an arithmetic number, because the mean of its divisors is an integer number (160827786).

Almost surely, 2^1378523820 is an apocalyptic number.

1378523820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1378523820 is an abundant number, since it is smaller than the sum of its proper divisors (2481343044).

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

1378523820 is a wasteful number, since it uses less digits than its factorization.

1378523820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22975409 (or 22975407 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 1378523820 is about 37128.4772108957. The cubic root of 1378523820 is about 1112.9391628953.

The spelling of 1378523820 in words is "one billion, three hundred seventy-eight million, five hundred twenty-three thousand, eight hundred twenty".