1620133644 has 12 divisors (see below), whose sum is σ = 3780311864. Its totient is φ = 540044544.

The previous prime is 1620133637. The next prime is 1620133649. The reversal of 1620133644 is 4463310261.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (1620133649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67505557 + ... + 67505580.

Almost surely, 2^1620133644 is an apocalyptic number.

It is an amenable number.

1620133644 is an abundant number, since it is smaller than the sum of its proper divisors (2160178220).

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

1620133644 is a wasteful number, since it uses less digits than its factorization.

1620133644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135011144 (or 135011142 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 1620133644 is about 40250.8837666951. The cubic root of 1620133644 is about 1174.4925876707.

The spelling of 1620133644 in words is "one billion, six hundred twenty million, one hundred thirty-three thousand, six hundred forty-four".