1921428985 has 32 divisors (see below), whose sum is σ = 2733477120. Its totient is φ = 1269209088.

The previous prime is 1921428967. The next prime is 1921428991. The reversal of 1921428985 is 5898241291.

It is not a de Polignac number, because 1921428985 - 2¹¹ = 1921426937 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 101121 + ... + 118609.

It is an arithmetic number, because the mean of its divisors is an integer number (85421160).

Almost surely, 2^1921428985 is an apocalyptic number.

It is an amenable number.

1921428985 is a deficient number, since it is larger than the sum of its proper divisors (812048135).

1921428985 is a wasteful number, since it uses less digits than its factorization.

1921428985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17617.

The product of its digits is 414720, while the sum is 49.

The square root of 1921428985 is about 43834.1075533653. The cubic root of 1921428985 is about 1243.2012723497.

The spelling of 1921428985 in words is "one billion, nine hundred twenty-one million, four hundred twenty-eight thousand, nine hundred eighty-five".