1504991621961 has 15 divisors (see below), whose sum is σ = 2248213854711. Its totient is φ = 1003320387288.

The previous prime is 1504991621893. The next prime is 1504991621993. The reversal of 1504991621961 is 1691261994051.

The square root of 1504991621961 is 1226781.

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

1504991621961 is a `hidden beast` number, since 1 + 5 + 0 + 4 + 9 + 9 + 1 + 621 + 9 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 115375029561 + 1389616592400 = 339669^2 + 1178820^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1504991621961 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1504991621898 and 1504991621907.

It is not an unprimeable number, because it can be changed into a prime (1504991620961) 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, 10972875 + ... + 11109183.

Almost surely, 2^{1504991621961} is an apocalyptic number.

1504991621961 is the 1226781-st square number.

1504991621961 is the 613391-st centered octagonal number.

It is an amenable number.

1504991621961 is a deficient number, since it is larger than the sum of its proper divisors (743222232750).

1504991621961 is an frugal number, since it uses more digits than its factorization.

1504991621961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272630 (or 136312 counting only the distinct ones).

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

The spelling of 1504991621961 in words is "one trillion, five hundred four billion, nine hundred ninety-one million, six hundred twenty-one thousand, nine hundred sixty-one".