1965228921 has 12 divisors (see below), whose sum is σ = 2839502848. Its totient is φ = 1309765464.

The previous prime is 1965228913. The next prime is 1965228943. The reversal of 1965228921 is 1298225691.

It is a happy number.

It is not a de Polignac number, because 1965228921 - 2³ = 1965228913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1965228901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1776 + ... + 62718.

Almost surely, 2^1965228921 is an apocalyptic number.

It is an amenable number.

1965228921 is a deficient number, since it is larger than the sum of its proper divisors (874273927).

1965228921 is a wasteful number, since it uses less digits than its factorization.

1965228921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64532 (or 64529 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 1965228921 is about 44330.9025511550. The cubic root of 1965228921 is about 1252.5768540217.

The spelling of 1965228921 in words is "one billion, nine hundred sixty-five million, two hundred twenty-eight thousand, nine hundred twenty-one".