1667667728 has 20 divisors (see below), whose sum is σ = 3255775248. Its totient is φ = 827467680.

The previous prime is 1667667691. The next prime is 1667667731. The reversal of 1667667728 is 8277667661.

It is a super-2 number, since 2×1667667728² = 5562231302025363968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 395726 + ... + 399917.

Almost surely, 2^1667667728 is an apocalyptic number.

It is an amenable number.

1667667728 is a deficient number, since it is larger than the sum of its proper divisors (1588107520).

1667667728 is a wasteful number, since it uses less digits than its factorization.

1667667728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795782 (or 795776 counting only the distinct ones).

The product of its digits is 7112448, while the sum is 56.

The square root of 1667667728 is about 40837.0876532595. The cubic root of 1667667728 is about 1185.8684318768.

The spelling of 1667667728 in words is "one billion, six hundred sixty-seven million, six hundred sixty-seven thousand, seven hundred twenty-eight".