1561003550 has 24 divisors (see below), whose sum is σ = 2907732792. Its totient is φ = 623484000.

The previous prime is 1561003511. The next prime is 1561003553. The reversal of 1561003550 is 553001651.

It is a super-2 number, since 2×1561003550² = 4873464166225205000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561003553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11960 + ... + 57140.

It is an arithmetic number, because the mean of its divisors is an integer number (121155533).

Almost surely, 2^1561003550 is an apocalyptic number.

1561003550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1561003550 is a deficient number, since it is larger than the sum of its proper divisors (1346729242).

1561003550 is a wasteful number, since it uses less digits than its factorization.

1561003550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45884 (or 45879 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 1561003550 is about 39509.5374561637. The cubic root of 1561003550 is about 1160.0266417781.

The spelling of 1561003550 in words is "one billion, five hundred sixty-one million, three thousand, five hundred fifty".