661065615 has 48 divisors (see below), whose sum is σ = 1336296000. Its totient is φ = 302194368.

The previous prime is 661065583. The next prime is 661065637. The reversal of 661065615 is 516560166.

It is not a de Polignac number, because 661065615 - 2⁵ = 661065583 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661065615.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5980 + ... + 36849.

It is an arithmetic number, because the mean of its divisors is an integer number (27839500).

Almost surely, 2^661065615 is an apocalyptic number.

661065615 is an abundant number, since it is smaller than the sum of its proper divisors (675230385).

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

661065615 is a wasteful number, since it uses less digits than its factorization.

661065615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42861 (or 42844 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 661065615 is about 25711.1962965553. The cubic root of 661065615 is about 871.1270964742.

The spelling of 661065615 in words is "six hundred sixty-one million, sixty-five thousand, six hundred fifteen".