661229787 has 8 divisors (see below), whose sum is σ = 882252304. Its totient is φ = 440513568.

The previous prime is 661229761. The next prime is 661229797. The reversal of 661229787 is 787922166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661229787 - 2¹⁴ = 661213403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661229797) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71488 + ... + 80205.

It is an arithmetic number, because the mean of its divisors is an integer number (110281538).

Almost surely, 2^661229787 is an apocalyptic number.

661229787 is a deficient number, since it is larger than the sum of its proper divisors (221022517).

661229787 is a wasteful number, since it uses less digits than its factorization.

661229787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153149.

The product of its digits is 508032, while the sum is 48.

The square root of 661229787 is about 25714.3887152699. The cubic root of 661229787 is about 871.1992037089.

The spelling of 661229787 in words is "six hundred sixty-one million, two hundred twenty-nine thousand, seven hundred eighty-seven".