1156551997 has 4 divisors (see below), whose sum is σ = 1158117760. Its totient is φ = 1154986236.

The previous prime is 1156551947. The next prime is 1156552003. The reversal of 1156551997 is 7991556511.

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 1156551997 - 2¹¹ = 1156549949 is a prime.

It is a super-2 number, since 2×1156551997² = 2675225043529376018, which contains 22 as substring.

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 1156551997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1156551917) 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, 781773 + ... + 783250.

It is an arithmetic number, because the mean of its divisors is an integer number (289529440).

Almost surely, 2^1156551997 is an apocalyptic number.

It is an amenable number.

1156551997 is a deficient number, since it is larger than the sum of its proper divisors (1565763).

1156551997 is an equidigital number, since it uses as much as digits as its factorization.

1156551997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1565762.

The product of its digits is 425250, while the sum is 49.

The square root of 1156551997 is about 34008.1166341213. The cubic root of 1156551997 is about 1049.6754845977.

The spelling of 1156551997 in words is "one billion, one hundred fifty-six million, five hundred fifty-one thousand, nine hundred ninety-seven".