2691421 has 2 divisors, whose sum is σ = 2691422. Its totient is φ = 2691420.

The previous prime is 2691401. The next prime is 2691427. The reversal of 2691421 is 1241962.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2595321 + 96100 = 1611^2 + 310^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2691421 is a prime.

It is a nialpdrome in base 12.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2691427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1345710 + 1345711.

It is an arithmetic number, because the mean of its divisors is an integer number (1345711).

2^2691421 is an apocalyptic number.

It is an amenable number.

2691421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2691421 is an equidigital number, since it uses as much as digits as its factorization.

2691421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

The square root of 2691421 is about 1640.5550889867. Note that the first 3 decimals coincide. The cubic root of 2691421 is about 139.1000263410.

The spelling of 2691421 in words is "two million, six hundred ninety-one thousand, four hundred twenty-one".