1620164400 has 120 divisors (see below), whose sum is σ = 5231284224. Its totient is φ = 428601600.

The previous prime is 1620164393. The next prime is 1620164437. The reversal of 1620164400 is 44610261.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 147085 + ... + 157715.

Almost surely, 2^1620164400 is an apocalyptic number.

1620164400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1620164400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2615642112).

1620164400 is an abundant number, since it is smaller than the sum of its proper divisors (3611119824).

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

1620164400 is a wasteful number, since it uses less digits than its factorization.

1620164400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10779 (or 10768 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 1620164400 is about 40251.2658186050. The cubic root of 1620164400 is about 1174.5000196636.

Adding to 1620164400 its reverse (44610261), we get a palindrome (1664774661).

It can be divided in two parts, 16201 and 64400, that added together give a triangular number (80601 = T₄₀₁).

The spelling of 1620164400 in words is "one billion, six hundred twenty million, one hundred sixty-four thousand, four hundred".