1681038021 has 8 divisors (see below), whose sum is σ = 2413798240. Its totient is φ = 1034484912.

The previous prime is 1681037993. The next prime is 1681038067. The reversal of 1681038021 is 1208301861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1681038021 - 2⁵ = 1681037989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1681038021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681048021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21551731 + ... + 21551808.

It is an arithmetic number, because the mean of its divisors is an integer number (301724780).

Almost surely, 2^1681038021 is an apocalyptic number.

It is an amenable number.

1681038021 is a deficient number, since it is larger than the sum of its proper divisors (732760219).

1681038021 is a wasteful number, since it uses less digits than its factorization.

1681038021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43103555.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1681038021 is about 41000.4636681099. The cubic root of 1681038021 is about 1189.0291780729.

Adding to 1681038021 its reverse (1208301861), we get a palindrome (2889339882).

The spelling of 1681038021 in words is "one billion, six hundred eighty-one million, thirty-eight thousand, twenty-one".