1641621731 has 2 divisors, whose sum is σ = 1641621732. Its totient is φ = 1641621730.

The previous prime is 1641621721. The next prime is 1641621767. The reversal of 1641621731 is 1371261461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1641621731 - 2¹⁴ = 1641605347 is a prime.

It is a super-2 number, since 2×1641621731² = 5389843815382872722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1641621721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820810865 + 820810866.

It is an arithmetic number, because the mean of its divisors is an integer number (820810866).

Almost surely, 2^1641621731 is an apocalyptic number.

1641621731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641621731 is an equidigital number, since it uses as much as digits as its factorization.

1641621731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 32.

The square root of 1641621731 is about 40516.9314114482. The cubic root of 1641621731 is about 1179.6622922804.

The spelling of 1641621731 in words is "one billion, six hundred forty-one million, six hundred twenty-one thousand, seven hundred thirty-one".