1661157623 has 2 divisors, whose sum is σ = 1661157624. Its totient is φ = 1661157622.

The previous prime is 1661157577. The next prime is 1661157653. The reversal of 1661157623 is 3267511661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1661157623 - 2¹⁴ = 1661141239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661157653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830578811 + 830578812.

It is an arithmetic number, because the mean of its divisors is an integer number (830578812).

Almost surely, 2^1661157623 is an apocalyptic number.

1661157623 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661157623 is an equidigital number, since it uses as much as digits as its factorization.

1661157623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 38.

The square root of 1661157623 is about 40757.3014685712. The cubic root of 1661157623 is about 1184.3233208102.

The spelling of 1661157623 in words is "one billion, six hundred sixty-one million, one hundred fifty-seven thousand, six hundred twenty-three".