1678007661 has 32 divisors (see below), whose sum is σ = 2592995328. Its totient is φ = 953936640.

The previous prime is 1678007659. The next prime is 1678007663. The reversal of 1678007661 is 1667008761.

It is an interprime number because it is at equal distance from previous prime (1678007659) and next prime (1678007663).

It is not a de Polignac number, because 1678007661 - 2¹ = 1678007659 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1678007663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 167356 + ... + 177098.

It is an arithmetic number, because the mean of its divisors is an integer number (81031104).

Almost surely, 2^1678007661 is an apocalyptic number.

1678007661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1678007661 is a deficient number, since it is larger than the sum of its proper divisors (914987667).

1678007661 is a wasteful number, since it uses less digits than its factorization.

1678007661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10081.

The product of its (nonzero) digits is 84672, while the sum is 42.

The square root of 1678007661 is about 40963.4918067296. The cubic root of 1678007661 is about 1188.3142718251.

The spelling of 1678007661 in words is "one billion, six hundred seventy-eight million, seven thousand, six hundred sixty-one".