661723055 has 32 divisors (see below), whose sum is σ = 952750080. Its totient is φ = 431631360.

The previous prime is 661723043. The next prime is 661723109. The reversal of 661723055 is 550327166.

It is not a de Polignac number, because 661723055 - 2¹⁴ = 661706671 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

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, 58847 + ... + 69183.

It is an arithmetic number, because the mean of its divisors is an integer number (29773440).

Almost surely, 2^661723055 is an apocalyptic number.

661723055 is a deficient number, since it is larger than the sum of its proper divisors (291027025).

661723055 is a wasteful number, since it uses less digits than its factorization.

661723055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10439.

The product of its (nonzero) digits is 37800, while the sum is 35.

The square root of 661723055 is about 25723.9782109999. The cubic root of 661723055 is about 871.4157839270.

The spelling of 661723055 in words is "six hundred sixty-one million, seven hundred twenty-three thousand, fifty-five".