661054040 has 64 divisors (see below), whose sum is σ = 1558137600. Its totient is φ = 251932032.

The previous prime is 661054039. The next prime is 661054049. The reversal of 661054040 is 40450166.

661054040 = T₃₃₃₃ + T₃₃₃₄ + ... + T₃₄₄₇.

It is a happy number.

661054040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661054049) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259091 + ... + 261629.

It is an arithmetic number, because the mean of its divisors is an integer number (24345900).

Almost surely, 2^661054040 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 661054040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (779068800).

661054040 is an abundant number, since it is smaller than the sum of its proper divisors (897083560).

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

661054040 is a wasteful number, since it uses less digits than its factorization.

661054040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2856 (or 2852 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 661054040 is about 25710.9711990815. The cubic root of 661054040 is about 871.1220120798.

The spelling of 661054040 in words is "six hundred sixty-one million, fifty-four thousand, forty".