1661274004 has 48 divisors (see below), whose sum is σ = 3243050496. Its totient is φ = 739440000.

The previous prime is 1661274001. The next prime is 1661274007. The reversal of 1661274004 is 4004721661.

It is an interprime number because it is at equal distance from previous prime (1661274001) and next prime (1661274007).

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661274001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 509379 + ... + 512629.

It is an arithmetic number, because the mean of its divisors is an integer number (67563552).

Almost surely, 2^1661274004 is an apocalyptic number.

It is an amenable number.

1661274004 is a deficient number, since it is larger than the sum of its proper divisors (1581776492).

1661274004 is a wasteful number, since it uses less digits than its factorization.

1661274004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3616 (or 3614 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 1661274004 is about 40758.7291754785. The cubic root of 1661274004 is about 1184.3509781322.

Adding to 1661274004 its reverse (4004721661), we get a palindrome (5665995665).

The spelling of 1661274004 in words is "one billion, six hundred sixty-one million, two hundred seventy-four thousand, four".