1901691061 has 2 divisors, whose sum is σ = 1901691062. Its totient is φ = 1901691060.

The previous prime is 1901691059. The next prime is 1901691067. The reversal of 1901691061 is 1601961091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1898780625 + 2910436 = 43575^2 + 1706^2 .

It is an emirp because it is prime and its reverse (1601961091) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1901691061 - 2¹ = 1901691059 is a prime.

Together with 1901691059, it forms a pair of twin primes.

1901691061 is a strobogrammatic number because it is the same when read upside-down.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1901691067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950845530 + 950845531.

It is an arithmetic number, because the mean of its divisors is an integer number (950845531).

Almost surely, 2^1901691061 is an apocalyptic number.

It is an amenable number.

1901691061 is a deficient number, since it is larger than the sum of its proper divisors (1).

1901691061 is an equidigital number, since it uses as much as digits as its factorization.

1901691061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 1901691061 is about 43608.3829211770. The cubic root of 1901691061 is about 1238.9296740815.

The spelling of 1901691061 in words is "one billion, nine hundred one million, six hundred ninety-one thousand, sixty-one".