1072661861 has 4 divisors (see below), whose sum is σ = 1072727424. Its totient is φ = 1072596300.

The previous prime is 1072661813. The next prime is 1072661899. The reversal of 1072661861 is 1681662701.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1072661861 - 2¹⁸ = 1072399717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1072651861) 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, 14306 + ... + 48476.

It is an arithmetic number, because the mean of its divisors is an integer number (268181856).

Almost surely, 2^1072661861 is an apocalyptic number.

It is an amenable number.

1072661861 is a deficient number, since it is larger than the sum of its proper divisors (65563).

1072661861 is an equidigital number, since it uses as much as digits as its factorization.

1072661861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65562.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 1072661861 is about 32751.5169267013. The cubic root of 1072661861 is about 1023.6565738437.

The spelling of 1072661861 in words is "one billion, seventy-two million, six hundred sixty-one thousand, eight hundred sixty-one".