40738981921 has 27 divisors (see below), whose sum is σ = 45697982449. Its totient is φ = 36290652200.

The previous prime is 40738981901. The next prime is 40738981931. The reversal of 40738981921 is 12918983704.

The square root of 40738981921 is 201839.

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

It is not a de Polignac number, because 40738981921 - 2¹¹ = 40738979873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40738981901) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 130993356 + ... + 130993666.

Almost surely, 2^40738981921 is an apocalyptic number.

40738981921 is the 201839-th square number.

40738981921 is the 100920-th centered octagonal number.

It is an amenable number.

40738981921 is a deficient number, since it is larger than the sum of its proper divisors (4959000528).

40738981921 is an frugal number, since it uses more digits than its factorization.

40738981921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762 (or 381 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 52.

The spelling of 40738981921 in words is "forty billion, seven hundred thirty-eight million, nine hundred eighty-one thousand, nine hundred twenty-one".