1261440210 has 32 divisors (see below), whose sum is σ = 3186797760. Its totient is φ = 318679488.

The previous prime is 1261440161. The next prime is 1261440233. The reversal of 1261440210 is 120441621.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1105957 + ... + 1107096.

It is an arithmetic number, because the mean of its divisors is an integer number (99587430).

Almost surely, 2^1261440210 is an apocalyptic number.

1261440210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1261440210 is an abundant number, since it is smaller than the sum of its proper divisors (1925357550).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1261440210 is a wasteful number, since it uses less digits than its factorization.

1261440210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2213082.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 1261440210 is about 35516.7595650279. The cubic root of 1261440210 is about 1080.4936614901.

Adding to 1261440210 its reverse (120441621), we get a palindrome (1381881831).

The spelling of 1261440210 in words is "one billion, two hundred sixty-one million, four hundred forty thousand, two hundred ten".