15621621645546 has 96 divisors (see below), whose sum is σ = 39123647222400. Its totient is φ = 4412391667200.

The previous prime is 15621621645527. The next prime is 15621621645551. The reversal of 15621621645546 is 64554612612651.

It is a happy number.

15621621645546 is a `hidden beast` number, since 1 + 5 + 6 + 2 + 1 + 6 + 21 + 64 + 554 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 15621621645492 and 15621621645501.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 64932345 + ... + 65172483.

It is an arithmetic number, because the mean of its divisors is an integer number (407537991900).

Almost surely, 2^{15621621645546} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15621621645546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19561823611200).

15621621645546 is an abundant number, since it is smaller than the sum of its proper divisors (23502025576854).

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

15621621645546 is a wasteful number, since it uses less digits than its factorization.

15621621645546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246044 (or 246041 counting only the distinct ones).

The product of its digits is 10368000, while the sum is 54.

The spelling of 15621621645546 in words is "fifteen trillion, six hundred twenty-one billion, six hundred twenty-one million, six hundred forty-five thousand, five hundred forty-six".