919825921 has 4 divisors (see below), whose sum is σ = 1051229632. Its totient is φ = 788422212.

The previous prime is 919825897. The next prime is 919825927. The reversal of 919825921 is 129528919.

919825921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 919825921 - 2⁵ = 919825889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (919825927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65701845 + ... + 65701858.

It is an arithmetic number, because the mean of its divisors is an integer number (262807408).

Almost surely, 2^919825921 is an apocalyptic number.

It is an amenable number.

919825921 is a deficient number, since it is larger than the sum of its proper divisors (131403711).

919825921 is a wasteful number, since it uses less digits than its factorization.

919825921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131403710.

The product of its digits is 116640, while the sum is 46.

The square root of 919825921 is about 30328.6320331135. The cubic root of 919825921 is about 972.5274791283.

It can be divided in two parts, 91982 and 5921, that added together give a triangular number (97903 = T₄₄₂).

The spelling of 919825921 in words is "nine hundred nineteen million, eight hundred twenty-five thousand, nine hundred twenty-one".