947879661 has 4 divisors (see below), whose sum is σ = 1263839552. Its totient is φ = 631919772.

The previous prime is 947879633. The next prime is 947879677. The reversal of 947879661 is 166978749.

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 not a de Polignac number, because 947879661 - 2¹⁹ = 947355373 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 (947869661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157979941 + ... + 157979946.

It is an arithmetic number, because the mean of its divisors is an integer number (315959888).

Almost surely, 2^947879661 is an apocalyptic number.

It is an amenable number.

947879661 is a deficient number, since it is larger than the sum of its proper divisors (315959891).

947879661 is a wasteful number, since it uses less digits than its factorization.

947879661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315959890.

The product of its digits is 4572288, while the sum is 57.

The square root of 947879661 is about 30787.6543601490. The cubic root of 947879661 is about 982.3156613417.

The spelling of 947879661 in words is "nine hundred forty-seven million, eight hundred seventy-nine thousand, six hundred sixty-one".