661438848 has 96 divisors (see below), whose sum is σ = 2043853560. Its totient is φ = 188977152.

The previous prime is 661438837. The next prime is 661438859. The reversal of 661438848 is 848834166.

It is an interprime number because it is at equal distance from previous prime (661438837) and next prime (661438859).

It is a tau number, because it is divible by the number of its divisors (96).

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 661438797 and 661438806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1240 + ... + 36392.

Almost surely, 2^661438848 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661438848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1021926780).

661438848 is an abundant number, since it is smaller than the sum of its proper divisors (1382414712).

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

661438848 is a wasteful number, since it uses less digits than its factorization.

661438848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35184 (or 35165 counting only the distinct ones).

The product of its digits is 884736, while the sum is 48.

The square root of 661438848 is about 25718.4534527253. The cubic root of 661438848 is about 871.2910097086.

The spelling of 661438848 in words is "six hundred sixty-one million, four hundred thirty-eight thousand, eight hundred forty-eight".