1256061251 has 4 divisors (see below), whose sum is σ = 1256176104. Its totient is φ = 1255946400.

The previous prime is 1256061239. The next prime is 1256061259. The reversal of 1256061251 is 1521606521.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1256061251 - 2²² = 1251866947 is a prime.

It is a super-4 number, since 4×1256061251⁴ (a number of 37 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256061259) 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, 39065 + ... + 63546.

It is an arithmetic number, because the mean of its divisors is an integer number (314044026).

Almost surely, 2^1256061251 is an apocalyptic number.

1256061251 is a deficient number, since it is larger than the sum of its proper divisors (114853).

1256061251 is a wasteful number, since it uses less digits than its factorization.

1256061251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114852.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 1256061251 is about 35440.9544312791. The cubic root of 1256061251 is about 1078.9556808948.

Adding to 1256061251 its reverse (1521606521), we get a palindrome (2777667772).

The spelling of 1256061251 in words is "one billion, two hundred fifty-six million, sixty-one thousand, two hundred fifty-one".