1837138978921 has 9 divisors (see below), whose sum is σ = 1840380049911. Its totient is φ = 1833903612864.

The previous prime is 1837138978897. The next prime is 1837138978981. The reversal of 1837138978921 is 1298798317381.

The square root of 1837138978921 is 1355411.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 35423380521 + 1801715598400 = 188211^2 + 1342280^2 .

It is not a de Polignac number, because 1837138978921 - 2¹¹ = 1837138976873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1837138978981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1259176090 + ... + 1259177548.

Almost surely, 2^{1837138978921} is an apocalyptic number.

1837138978921 is the 1355411-st square number.

1837138978921 is the 677706-th centered octagonal number.

It is an amenable number.

1837138978921 is a deficient number, since it is larger than the sum of its proper divisors (3241070990).

1837138978921 is an frugal number, since it uses more digits than its factorization.

1837138978921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4776 (or 2388 counting only the distinct ones).

The product of its digits is 36578304, while the sum is 67.

The spelling of 1837138978921 in words is "one trillion, eight hundred thirty-seven billion, one hundred thirty-eight million, nine hundred seventy-eight thousand, nine hundred twenty-one".