681012021 has 8 divisors (see below), whose sum is σ = 908139744. Its totient is φ = 453946160.

The previous prime is 681011987. The next prime is 681012103. The reversal of 681012021 is 120210186.

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

It is a cyclic number.

It is not a de Polignac number, because 681012021 - 2¹⁰ = 681010997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681012721) 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, 26470 + ... + 45416.

It is an arithmetic number, because the mean of its divisors is an integer number (113517468).

Almost surely, 2^681012021 is an apocalyptic number.

It is an amenable number.

681012021 is a deficient number, since it is larger than the sum of its proper divisors (227127723).

681012021 is a wasteful number, since it uses less digits than its factorization.

681012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30931.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 681012021 is about 26096.2070232438. The cubic root of 681012021 is about 879.8019617206.

The spelling of 681012021 in words is "six hundred eighty-one million, twelve thousand, twenty-one".