1551964091 has 4 divisors (see below), whose sum is σ = 1552043400. Its totient is φ = 1551884784.

The previous prime is 1551964039. The next prime is 1551964097. The reversal of 1551964091 is 1904691551.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1551964091 - 2¹⁴ = 1551947707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1551964097) 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, 13040 + ... + 57218.

It is an arithmetic number, because the mean of its divisors is an integer number (388010850).

Almost surely, 2^1551964091 is an apocalyptic number.

1551964091 is a deficient number, since it is larger than the sum of its proper divisors (79309).

1551964091 is an equidigital number, since it uses as much as digits as its factorization.

1551964091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79308.

The product of its (nonzero) digits is 48600, while the sum is 41.

The square root of 1551964091 is about 39394.9754537301. The cubic root of 1551964091 is about 1157.7831449717.

The spelling of 1551964091 in words is "one billion, five hundred fifty-one million, nine hundred sixty-four thousand, ninety-one".