1091647997 has 4 divisors (see below), whose sum is σ = 1190888736. Its totient is φ = 992407260.

The previous prime is 1091647993. The next prime is 1091648017. The reversal of 1091647997 is 7997461901.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1091647997 - 2² = 1091647993 is a prime.

It is a super-2 number, since 2×1091647997² = 2383390698708224018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091647993) 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, 49620353 + ... + 49620374.

It is an arithmetic number, because the mean of its divisors is an integer number (297722184).

Almost surely, 2^1091647997 is an apocalyptic number.

It is an amenable number.

1091647997 is a deficient number, since it is larger than the sum of its proper divisors (99240739).

1091647997 is an equidigital number, since it uses as much as digits as its factorization.

1091647997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99240738.

The product of its (nonzero) digits is 857304, while the sum is 53.

The square root of 1091647997 is about 33040.0968067589. The cubic root of 1091647997 is about 1029.6608670797.

The spelling of 1091647997 in words is "one billion, ninety-one million, six hundred forty-seven thousand, nine hundred ninety-seven".