1221031510151 has 4 divisors (see below), whose sum is σ = 1247010904032. Its totient is φ = 1195052116272.

The previous prime is 1221031510129. The next prime is 1221031510211. The reversal of 1221031510151 is 1510151301221.

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-1221031510151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221031513151) 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, 12989696870 + ... + 12989696963.

It is an arithmetic number, because the mean of its divisors is an integer number (311752726008).

Almost surely, 2^{1221031510151} is an apocalyptic number.

1221031510151 is a deficient number, since it is larger than the sum of its proper divisors (25979393881).

1221031510151 is an equidigital number, since it uses as much as digits as its factorization.

1221031510151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25979393880.

The product of its (nonzero) digits is 300, while the sum is 23.

Adding to 1221031510151 its reverse (1510151301221), we get a palindrome (2731182811372).

The spelling of 1221031510151 in words is "one trillion, two hundred twenty-one billion, thirty-one million, five hundred ten thousand, one hundred fifty-one".