920851981 has 8 divisors (see below), whose sum is σ = 1060689920. Its totient is φ = 783085968.

The previous prime is 920851979. The next prime is 920851991. The reversal of 920851981 is 189158029.

920851981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 920851981 - 2¹ = 920851979 is a prime.

It is a super-2 number, since 2×920851981² = 1695936741823248722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (920851901) 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, 517026 + ... + 518803.

It is an arithmetic number, because the mean of its divisors is an integer number (132586240).

Almost surely, 2^920851981 is an apocalyptic number.

It is an amenable number.

920851981 is a deficient number, since it is larger than the sum of its proper divisors (139837939).

920851981 is a wasteful number, since it uses less digits than its factorization.

920851981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1035963.

The product of its (nonzero) digits is 51840, while the sum is 43.

The square root of 920851981 is about 30345.5430170561. The cubic root of 920851981 is about 972.8889608364. Note that the first 3 decimals are identical.

The spelling of 920851981 in words is "nine hundred twenty million, eight hundred fifty-one thousand, nine hundred eighty-one".