1561237051 has 4 divisors (see below), whose sum is σ = 1703167704. Its totient is φ = 1419306400.

The previous prime is 1561237009. The next prime is 1561237063. The reversal of 1561237051 is 1507321651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1561237051 - 2²¹ = 1559139899 is a prime.

It is a super-2 number, since 2×1561237051² = 4874922258830353202, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561237081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70965310 + ... + 70965331.

It is an arithmetic number, because the mean of its divisors is an integer number (425791926).

Almost surely, 2^1561237051 is an apocalyptic number.

1561237051 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1561237051 is a deficient number, since it is larger than the sum of its proper divisors (141930653).

1561237051 is a wasteful number, since it uses less digits than its factorization.

1561237051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141930652.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 1561237051 is about 39512.4923410306. The cubic root of 1561237051 is about 1160.0844793310.

The spelling of 1561237051 in words is "one billion, five hundred sixty-one million, two hundred thirty-seven thousand, fifty-one".