1561333197 has 8 divisors (see below), whose sum is σ = 2148931840. Its totient is φ = 1007311680.

The previous prime is 1561333181. The next prime is 1561333229. The reversal of 1561333197 is 7913331651.

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

It is not a de Polignac number, because 1561333197 - 2⁴ = 1561333181 is a prime.

It is a super-2 number, since 2×1561333197² = 4875522704108481618, 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 (1561373197) 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, 8394172 + ... + 8394357.

It is an arithmetic number, because the mean of its divisors is an integer number (268616480).

Almost surely, 2^1561333197 is an apocalyptic number.

It is an amenable number.

1561333197 is a deficient number, since it is larger than the sum of its proper divisors (587598643).

1561333197 is a wasteful number, since it uses less digits than its factorization.

1561333197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16788563.

The product of its digits is 51030, while the sum is 39.

The square root of 1561333197 is about 39513.7089754936. The cubic root of 1561333197 is about 1160.1082927536.

It can be divided in two parts, 156133 and 3197, that added together give a triangular number (159330 = T₅₆₄).

The spelling of 1561333197 in words is "one billion, five hundred sixty-one million, three hundred thirty-three thousand, one hundred ninety-seven".