661277148 has 72 divisors (see below), whose sum is σ = 1798296192. Its totient is φ = 188578656.

The previous prime is 661277129. The next prime is 661277171. The reversal of 661277148 is 841772166.

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

It is a congruent number.

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, 568015 + ... + 569177.

It is an arithmetic number, because the mean of its divisors is an integer number (24976336).

Almost surely, 2^661277148 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 661277148, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899148096).

661277148 is an abundant number, since it is smaller than the sum of its proper divisors (1137019044).

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

661277148 is a wasteful number, since it uses less digits than its factorization.

661277148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151 (or 2142 counting only the distinct ones).

The product of its digits is 112896, while the sum is 42.

The square root of 661277148 is about 25715.3096034250. The cubic root of 661277148 is about 871.2200032762.

The spelling of 661277148 in words is "six hundred sixty-one million, two hundred seventy-seven thousand, one hundred forty-eight".