201997951 has 2 divisors, whose sum is σ = 201997952. Its totient is φ = 201997950.

The previous prime is 201997931. The next prime is 201997973. The reversal of 201997951 is 159799102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 201997951 - 2⁷ = 201997823 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201997898 and 201997907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201997931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100998975 + 100998976.

It is an arithmetic number, because the mean of its divisors is an integer number (100998976).

Almost surely, 2^201997951 is an apocalyptic number.

201997951 is a deficient number, since it is larger than the sum of its proper divisors (1).

201997951 is an equidigital number, since it uses as much as digits as its factorization.

201997951 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51030, while the sum is 43.

The square root of 201997951 is about 14212.5983198006. The cubic root of 201997951 is about 586.7444469375.

The spelling of 201997951 in words is "two hundred one million, nine hundred ninety-seven thousand, nine hundred fifty-one".