651212157 has 4 divisors (see below), whose sum is σ = 868282880. Its totient is φ = 434141436.

The previous prime is 651212153. The next prime is 651212171. The reversal of 651212157 is 751212156.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 651212157 - 2² = 651212153 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 (651212153) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 108535357 + ... + 108535362.

It is an arithmetic number, because the mean of its divisors is an integer number (217070720).

Almost surely, 2^651212157 is an apocalyptic number.

It is an amenable number.

651212157 is a deficient number, since it is larger than the sum of its proper divisors (217070723).

651212157 is a wasteful number, since it uses less digits than its factorization.

651212157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217070722.

The product of its digits is 4200, while the sum is 30.

The square root of 651212157 is about 25518.8588498781. The cubic root of 651212157 is about 866.7772416279. Note that the first 3 decimals are identical.

Subtracting 651212157 from its reverse (751212156), we obtain a palindrome (99999999).

The spelling of 651212157 in words is "six hundred fifty-one million, two hundred twelve thousand, one hundred fifty-seven".