1721427139 has 2 divisors, whose sum is σ = 1721427140. Its totient is φ = 1721427138.

The previous prime is 1721427119. The next prime is 1721427199. The reversal of 1721427139 is 9317241271.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1721427139 - 2⁹ = 1721426627 is a prime.

It is a super-2 number, since 2×1721427139² = 5926622789771450642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1721427098 and 1721427107.

It is not a weakly prime, because it can be changed into another prime (1721427119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860713569 + 860713570.

It is an arithmetic number, because the mean of its divisors is an integer number (860713570).

Almost surely, 2^1721427139 is an apocalyptic number.

1721427139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1721427139 is an equidigital number, since it uses as much as digits as its factorization.

1721427139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 37.

The square root of 1721427139 is about 41490.0848275826. The cubic root of 1721427139 is about 1198.4765711871.

The spelling of 1721427139 in words is "one billion, seven hundred twenty-one million, four hundred twenty-seven thousand, one hundred thirty-nine".