15516422149921 has 27 divisors (see below), whose sum is σ = 19840157826867. Its totient is φ = 12090482213040.

The previous prime is 15516422149871. The next prime is 15516422149927. The reversal of 15516422149921 is 12994122461551.

The square root of 15516422149921 is 3939089.

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., 15418305358225 + 98116791696 = 3926615^2 + 313236^2 .

It is not a de Polignac number, because 15516422149921 - 2¹³ = 15516422141729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15516422149927) 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, 303284275 + ... + 303335431.

Almost surely, 2^{15516422149921} is an apocalyptic number.

15516422149921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

15516422149921 is the 3939089-th square number.

15516422149921 is the 1969545-th centered octagonal number.

It is an amenable number.

15516422149921 is a deficient number, since it is larger than the sum of its proper divisors (4323735676946).

15516422149921 is an frugal number, since it uses more digits than its factorization.

15516422149921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102350 (or 51175 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 52.

The spelling of 15516422149921 in words is "fifteen trillion, five hundred sixteen billion, four hundred twenty-two million, one hundred forty-nine thousand, nine hundred twenty-one".