2139947 has 2 divisors, whose sum is σ = 2139948. Its totient is φ = 2139946.

The previous prime is 2139937. The next prime is 2139953. The reversal of 2139947 is 7499312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2139947 - 2⁴ = 2139931 is a prime.

It is not a weakly prime, because it can be changed into another prime (2139937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1069973 + 1069974.

It is an arithmetic number, because the mean of its divisors is an integer number (1069974).

2^2139947 is an apocalyptic number.

2139947 is a deficient number, since it is larger than the sum of its proper divisors (1).

2139947 is an equidigital number, since it uses as much as digits as its factorization.

2139947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 35.

The square root of 2139947 is about 1462.8557686936. The cubic root of 2139947 is about 128.8648103994.

It can be divided in two parts, 213 and 9947, that multiplied together give a triangular number (2118711 = T₂₀₅₈).

The spelling of 2139947 in words is "two million, one hundred thirty-nine thousand, nine hundred forty-seven".