1261644101 has 8 divisors (see below), whose sum is σ = 1315116000. Its totient is φ = 1208836720.

The previous prime is 1261644067. The next prime is 1261644113. The reversal of 1261644101 is 1014461621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261644101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261644121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162251 + ... + 169848.

It is an arithmetic number, because the mean of its divisors is an integer number (164389500).

Almost surely, 2^1261644101 is an apocalyptic number.

It is an amenable number.

1261644101 is a deficient number, since it is larger than the sum of its proper divisors (53471899).

1261644101 is a wasteful number, since it uses less digits than its factorization.

1261644101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332259.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 1261644101 is about 35519.6297981834. The cubic root of 1261644101 is about 1080.5518730124.

The spelling of 1261644101 in words is "one billion, two hundred sixty-one million, six hundred forty-four thousand, one hundred one".