661892400 has 180 divisors, whose sum is σ = 2473813888. Its totient is φ = 162915840.

The previous prime is 661892393. The next prime is 661892423. The reversal of 661892400 is 4298166.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 39729 + ... + 53871.

Almost surely, 2^661892400 is an apocalyptic number.

661892400 is a gapful number since it is divisible by the number (60) 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 661892400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1236906944).

661892400 is an abundant number, since it is smaller than the sum of its proper divisors (1811921488).

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

661892400 is a wasteful number, since it uses less digits than its factorization.

661892400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14180 (or 14166 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 661892400 is about 25727.2695791839. The cubic root of 661892400 is about 871.4901137734.

The spelling of 661892400 in words is "six hundred sixty-one million, eight hundred ninety-two thousand, four hundred".