1561550 has 12 divisors (see below), whose sum is σ = 2904576. Its totient is φ = 624600.

The previous prime is 1561541. The next prime is 1561559. The reversal of 1561550 is 551651.

It is an interprime number because it is at equal distance from previous prime (1561541) and next prime (1561559).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15566 + ... + 15665.

It is an arithmetic number, because the mean of its divisors is an integer number (242048).

2^1561550 is an apocalyptic number.

1561550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1561550 is a deficient number, since it is larger than the sum of its proper divisors (1343026).

1561550 is a wasteful number, since it uses less digits than its factorization.

1561550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31243 (or 31238 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 1561550 is about 1249.6199422224. The cubic root of 1561550 is about 116.0161986891.

The spelling of 1561550 in words is "one million, five hundred sixty-one thousand, five hundred fifty".