1261631254 has 64 divisors (see below), whose sum is σ = 2220099840. Its totient is φ = 533191680.

The previous prime is 1261631243. The next prime is 1261631317. The reversal of 1261631254 is 4521361621.

It is a happy number.

It is a super-2 number, since 2×1261631254² = 3183426842139225032, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1143267 + ... + 1144369.

It is an arithmetic number, because the mean of its divisors is an integer number (34689060).

Almost surely, 2^1261631254 is an apocalyptic number.

1261631254 is a deficient number, since it is larger than the sum of its proper divisors (958468586).

1261631254 is a wasteful number, since it uses less digits than its factorization.

1261631254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1225.

The product of its digits is 8640, while the sum is 31.

The square root of 1261631254 is about 35519.4489540590. The cubic root of 1261631254 is about 1080.5482053386.

Adding to 1261631254 its reverse (4521361621), we get a palindrome (5782992875).

The spelling of 1261631254 in words is "one billion, two hundred sixty-one million, six hundred thirty-one thousand, two hundred fifty-four".