1921145690916 has 45 divisors (see below), whose sum is σ = 5022319544011. Its totient is φ = 640373580648.

The previous prime is 1921145690911. The next prime is 1921145690917. The reversal of 1921145690916 is 6190965411291.

The square root of 1921145690916 is 1386054.

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

1921145690916 is a `hidden beast` number, since 1 + 9 + 2 + 11 + 456 + 90 + 91 + 6 = 666.

It is a super-3 number, since 3×1921145690916³ (a number of 38 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1921145690911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 24910471 + ... + 24987473.

Almost surely, 2^{1921145690916} is an apocalyptic number.

1921145690916 is the 1386054-th square number.

It is an amenable number.

1921145690916 is an abundant number, since it is smaller than the sum of its proper divisors (3101173853095).

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

1921145690916 is an frugal number, since it uses more digits than its factorization.

1921145690916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154022 (or 77008 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 54.

The spelling of 1921145690916 in words is "one trillion, nine hundred twenty-one billion, one hundred forty-five million, six hundred ninety thousand, nine hundred sixteen".