1821153554545 has 16 divisors (see below), whose sum is σ = 2353525836480. Its totient is φ = 1344831804864.

The previous prime is 1821153554531. The next prime is 1821153554551. The reversal of 1821153554545 is 5454553511281.

It is a cyclic number.

It is not a de Polignac number, because 1821153554545 - 2³¹ = 1819006070897 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5289142 + ... + 5622928.

It is an arithmetic number, because the mean of its divisors is an integer number (147095364780).

Almost surely, 2^{1821153554545} is an apocalyptic number.

It is an amenable number.

1821153554545 is a deficient number, since it is larger than the sum of its proper divisors (532372281935).

1821153554545 is a wasteful number, since it uses less digits than its factorization.

1821153554545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417744.

The product of its digits is 2400000, while the sum is 49.

The spelling of 1821153554545 in words is "one trillion, eight hundred twenty-one billion, one hundred fifty-three million, five hundred fifty-four thousand, five hundred forty-five".