2151591697 has 2 divisors, whose sum is σ = 2151591698. Its totient is φ = 2151591696.

The previous prime is 2151591671. The next prime is 2151591769. The reversal of 2151591697 is 7961951512.

Together with next prime (2151591769) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1889119296 + 262472401 = 43464^2 + 16201^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2151591697 is a prime.

It is not a weakly prime, because it can be changed into another prime (2151592697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1075795848 + 1075795849.

It is an arithmetic number, because the mean of its divisors is an integer number (1075795849).

Almost surely, 2^2151591697 is an apocalyptic number.

It is an amenable number.

2151591697 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151591697 is an equidigital number, since it uses as much as digits as its factorization.

2151591697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 170100, while the sum is 46.

The square root of 2151591697 is about 46385.2530121374. The cubic root of 2151591697 is about 1290.9813050901.

The spelling of 2151591697 in words is "two billion, one hundred fifty-one million, five hundred ninety-one thousand, six hundred ninety-seven".