661155002 has 4 divisors (see below), whose sum is σ = 991732506. Its totient is φ = 330577500.

The previous prime is 661154983. The next prime is 661155017. The reversal of 661155002 is 200551166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 200551166 = 2 ⋅100275583.

It can be written as a sum of positive squares in only one way, i.e., 639634681 + 21520321 = 25291^2 + 4639^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165288749 + ... + 165288752.

Almost surely, 2^661155002 is an apocalyptic number.

661155002 is a deficient number, since it is larger than the sum of its proper divisors (330577504).

661155002 is a wasteful number, since it uses less digits than its factorization.

661155002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330577503.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 661155002 is about 25712.9345271986. The cubic root of 661155002 is about 871.1663582996.

It can be divided in two parts, 66115 and 5002, that added together give a palindrome (71117).

The spelling of 661155002 in words is "six hundred sixty-one million, one hundred fifty-five thousand, two".