1671970821 has 16 divisors (see below), whose sum is σ = 2264532480. Its totient is φ = 1097141760.

The previous prime is 1671970819. The next prime is 1671970829. The reversal of 1671970821 is 1280791761.

It is not a de Polignac number, because 1671970821 - 2¹ = 1671970819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1671970829) 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, 45501 + ... + 73581.

It is an arithmetic number, because the mean of its divisors is an integer number (141533280).

Almost surely, 2^1671970821 is an apocalyptic number.

It is an amenable number.

1671970821 is a deficient number, since it is larger than the sum of its proper divisors (592561659).

1671970821 is a wasteful number, since it uses less digits than its factorization.

1671970821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28396.

The product of its (nonzero) digits is 42336, while the sum is 42.

The square root of 1671970821 is about 40889.7398010797. The cubic root of 1671970821 is about 1186.8875236554.

The spelling of 1671970821 in words is "one billion, six hundred seventy-one million, nine hundred seventy thousand, eight hundred twenty-one".