661274777 has 4 divisors (see below), whose sum is σ = 663180816. Its totient is φ = 659368740.

The previous prime is 661274741. The next prime is 661274813. The reversal of 661274777 is 777472166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (661274741) and next prime (661274813).

It is a cyclic number.

It is not a de Polignac number, because 661274777 - 2¹² = 661270681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661274707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 952499 + ... + 953192.

It is an arithmetic number, because the mean of its divisors is an integer number (165795204).

Almost surely, 2^661274777 is an apocalyptic number.

It is an amenable number.

661274777 is a deficient number, since it is larger than the sum of its proper divisors (1906039).

661274777 is a wasteful number, since it uses less digits than its factorization.

661274777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906038.

The product of its digits is 691488, while the sum is 47.

The square root of 661274777 is about 25715.2635024415. The cubic root of 661274777 is about 871.2189620259.

The spelling of 661274777 in words is "six hundred sixty-one million, two hundred seventy-four thousand, seven hundred seventy-seven".