1378137990 has 32 divisors (see below), whose sum is σ = 3313683936. Its totient is φ = 366819840.

The previous prime is 1378137983. The next prime is 1378137991. The reversal of 1378137990 is 997318731.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378137991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26227 + ... + 58686.

It is an arithmetic number, because the mean of its divisors is an integer number (103552623).

Almost surely, 2^1378137990 is an apocalyptic number.

1378137990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1378137990 is an abundant number, since it is smaller than the sum of its proper divisors (1935545946).

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

1378137990 is a wasteful number, since it uses less digits than its factorization.

1378137990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85464.

The product of its (nonzero) digits is 285768, while the sum is 48.

The square root of 1378137990 is about 37123.2809703022. The cubic root of 1378137990 is about 1112.8353210468.

The spelling of 1378137990 in words is "one billion, three hundred seventy-eight million, one hundred thirty-seven thousand, nine hundred ninety".