1561993153 has 4 divisors (see below), whose sum is σ = 1785135040. Its totient is φ = 1338851268.

The previous prime is 1561993151. The next prime is 1561993163. The reversal of 1561993153 is 3513991651.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3513991651 = 19 ⋅184946929.

It is a cyclic number.

It is not a de Polignac number, because 1561993153 - 2¹ = 1561993151 is a prime.

It is a super-2 number, since 2×1561993153² = 4879645220037762818, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561993151) 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, 111570933 + ... + 111570946.

It is an arithmetic number, because the mean of its divisors is an integer number (446283760).

Almost surely, 2^1561993153 is an apocalyptic number.

It is an amenable number.

1561993153 is a deficient number, since it is larger than the sum of its proper divisors (223141887).

1561993153 is an equidigital number, since it uses as much as digits as its factorization.

1561993153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223141886.

The product of its digits is 109350, while the sum is 43.

The square root of 1561993153 is about 39522.0590683228. The cubic root of 1561993153 is about 1160.2717241472.

The spelling of 1561993153 in words is "one billion, five hundred sixty-one million, nine hundred ninety-three thousand, one hundred fifty-three".