1553545644 has 24 divisors (see below), whose sum is σ = 4142788608. Its totient is φ = 443870160.

The previous prime is 1553545639. The next prime is 1553545657. The reversal of 1553545644 is 4465453551.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1553545596 and 1553545605.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9247212 + ... + 9247379.

It is an arithmetic number, because the mean of its divisors is an integer number (172616192).

Almost surely, 2^1553545644 is an apocalyptic number.

1553545644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1553545644 is an abundant number, since it is smaller than the sum of its proper divisors (2589242964).

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

1553545644 is a wasteful number, since it uses less digits than its factorization.

1553545644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18494605 (or 18494603 counting only the distinct ones).

The product of its digits is 720000, while the sum is 42.

The square root of 1553545644 is about 39415.0433717889. The cubic root of 1553545644 is about 1158.1762970570.

The spelling of 1553545644 in words is "one billion, five hundred fifty-three million, five hundred forty-five thousand, six hundred forty-four".