1958398691 has 8 divisors (see below), whose sum is σ = 2074512384. Its totient is φ = 1842386560.

The previous prime is 1958398649. The next prime is 1958398693. The reversal of 1958398691 is 1968938591.

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

It is not a de Polignac number, because 1958398691 - 2⁶ = 1958398627 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1958398691.

It is not an unprimeable number, because it can be changed into a prime (1958398693) 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, 16286 + ... + 64668.

It is an arithmetic number, because the mean of its divisors is an integer number (259314048).

Almost surely, 2^1958398691 is an apocalyptic number.

1958398691 is a deficient number, since it is larger than the sum of its proper divisors (116113693).

1958398691 is a wasteful number, since it uses less digits than its factorization.

1958398691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50781.

The product of its digits is 4199040, while the sum is 59.

The square root of 1958398691 is about 44253.7986053175. The cubic root of 1958398691 is about 1251.1240429989.

The spelling of 1958398691 in words is "one billion, nine hundred fifty-eight million, three hundred ninety-eight thousand, six hundred ninety-one".