2951395721 has 4 divisors (see below), whose sum is σ = 3125007252. Its totient is φ = 2777784192.

The previous prime is 2951395693. The next prime is 2951395729. The reversal of 2951395721 is 1275931592.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2317363321 + 634032400 = 48139^2 + 25180^2 .

It is a cyclic number.

It is not a de Polignac number, because 2951395721 - 2²² = 2947201417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2951395729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86805740 + ... + 86805773.

It is an arithmetic number, because the mean of its divisors is an integer number (781251813).

Almost surely, 2^2951395721 is an apocalyptic number.

It is an amenable number.

2951395721 is a deficient number, since it is larger than the sum of its proper divisors (173611531).

2951395721 is a wasteful number, since it uses less digits than its factorization.

2951395721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173611530.

The product of its digits is 170100, while the sum is 44.

The square root of 2951395721 is about 54326.7495898659. The cubic root of 2951395721 is about 1434.4182907723.

The spelling of 2951395721 in words is "two billion, nine hundred fifty-one million, three hundred ninety-five thousand, seven hundred twenty-one".