1271621261 has 8 divisors (see below), whose sum is σ = 1315867800. Its totient is φ = 1227401280.

The previous prime is 1271621257. The next prime is 1271621287. The reversal of 1271621261 is 1621261721.

It can be written as a sum of positive squares in 4 ways, for example, as 118679236 + 1152942025 = 10894^2 + 33955^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1271621261 - 2² = 1271621257 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271621201) 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 7 ways as a sum of consecutive naturals, for example, 182795 + ... + 189623.

It is an arithmetic number, because the mean of its divisors is an integer number (164483475).

Almost surely, 2^1271621261 is an apocalyptic number.

It is an amenable number.

1271621261 is a deficient number, since it is larger than the sum of its proper divisors (44246539).

1271621261 is an equidigital number, since it uses as much as digits as its factorization.

1271621261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13279.

The product of its digits is 2016, while the sum is 29.

The square root of 1271621261 is about 35659.7989478348. The cubic root of 1271621261 is about 1083.3927546315.

Adding to 1271621261 its reverse (1621261721), we get a palindrome (2892882982).

The spelling of 1271621261 in words is "one billion, two hundred seventy-one million, six hundred twenty-one thousand, two hundred sixty-one".