87729961 has 6 divisors (see below), whose sum is σ = 96430586. Its totient is φ = 79754400.

The previous prime is 87729953. The next prime is 87729977. The reversal of 87729961 is 16992778.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 64304361 + 23425600 = 8019^2 + 4840^2 .

It is not a de Polignac number, because 87729961 - 2³ = 87729953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87729461) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 362400 + ... + 362641.

Almost surely, 2^87729961 is an apocalyptic number.

It is an amenable number.

87729961 is a deficient number, since it is larger than the sum of its proper divisors (8700625).

87729961 is a wasteful number, since it uses less digits than its factorization.

87729961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725063 (or 725052 counting only the distinct ones).

The product of its digits is 381024, while the sum is 49.

The square root of 87729961 is about 9366.4273338344. The cubic root of 87729961 is about 444.3405812137.

The spelling of 87729961 in words is "eighty-seven million, seven hundred twenty-nine thousand, nine hundred sixty-one".