1225501631 has 4 divisors (see below), whose sum is σ = 1227501432. Its totient is φ = 1223501832.

The previous prime is 1225501621. The next prime is 1225501681. The reversal of 1225501631 is 1361055221.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1225501631 is a prime.

It is a super-2 number, since 2×1225501631² = 3003708495167320322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1225501631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225501621) 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, 998981 + ... + 1000206.

It is an arithmetic number, because the mean of its divisors is an integer number (306875358).

Almost surely, 2^1225501631 is an apocalyptic number.

1225501631 is a deficient number, since it is larger than the sum of its proper divisors (1999801).

1225501631 is an equidigital number, since it uses as much as digits as its factorization.

1225501631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1999800.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 1225501631 is about 35007.1654236672. The cubic root of 1225501631 is about 1070.1335120325.

Adding to 1225501631 its reverse (1361055221), we get a palindrome (2586556852).

The spelling of 1225501631 in words is "one billion, two hundred twenty-five million, five hundred one thousand, six hundred thirty-one".