1928906391 has 24 divisors (see below), whose sum is σ = 2728441584. Its totient is φ = 1211938560.

The previous prime is 1928906387. The next prime is 1928906417. The reversal of 1928906391 is 1936098291.

It is not a de Polignac number, because 1928906391 - 2² = 1928906387 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1928906391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1928908391) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 208831 + ... + 217871.

It is an arithmetic number, because the mean of its divisors is an integer number (113685066).

Almost surely, 2^1928906391 is an apocalyptic number.

1928906391 is a deficient number, since it is larger than the sum of its proper divisors (799535193).

1928906391 is a wasteful number, since it uses less digits than its factorization.

1928906391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9279 (or 9260 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 48.

The square root of 1928906391 is about 43919.3168321184. The cubic root of 1928906391 is about 1244.8118597657.

The spelling of 1928906391 in words is "one billion, nine hundred twenty-eight million, nine hundred six thousand, three hundred ninety-one".