661271754 has 64 divisors (see below), whose sum is σ = 1563972480. Its totient is φ = 183755520.

The previous prime is 661271747. The next prime is 661271771. The reversal of 661271754 is 457172166.

661271754 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 132252 + ... + 137160.

It is an arithmetic number, because the mean of its divisors is an integer number (24437070).

Almost surely, 2^661271754 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661271754, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (781986240).

661271754 is an abundant number, since it is smaller than the sum of its proper divisors (902700726).

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

661271754 is a wasteful number, since it uses less digits than its factorization.

661271754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5095.

The product of its digits is 70560, while the sum is 39.

The square root of 661271754 is about 25715.2047240538. The cubic root of 661271754 is about 871.2176344391.

The spelling of 661271754 in words is "six hundred sixty-one million, two hundred seventy-one thousand, seven hundred fifty-four".