661982773 has 16 divisors (see below), whose sum is σ = 708134400. Its totient is φ = 617797440.

The previous prime is 661982747. The next prime is 661982777. The reversal of 661982773 is 377289166.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 661982773 - 2¹³ = 661974581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661982777) 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, 93523 + ... + 100351.

It is an arithmetic number, because the mean of its divisors is an integer number (44258400).

Almost surely, 2^661982773 is an apocalyptic number.

It is an amenable number.

661982773 is a deficient number, since it is larger than the sum of its proper divisors (46151627).

661982773 is a wasteful number, since it uses less digits than its factorization.

661982773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6972.

The product of its digits is 762048, while the sum is 49.

The square root of 661982773 is about 25729.0258851749. The cubic root of 661982773 is about 871.5297756036.

The spelling of 661982773 in words is "six hundred sixty-one million, nine hundred eighty-two thousand, seven hundred seventy-three".