1821649157 has 16 divisors (see below), whose sum is σ = 1896376320. Its totient is φ = 1748420352.

The previous prime is 1821649139. The next prime is 1821649261. The reversal of 1821649157 is 7519461281.

It is a cyclic number.

It is not a de Polignac number, because 1821649157 - 2¹² = 1821645061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821646157) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 998348 + ... + 1000170.

It is an arithmetic number, because the mean of its divisors is an integer number (118523520).

Almost surely, 2^1821649157 is an apocalyptic number.

It is an amenable number.

1821649157 is a deficient number, since it is larger than the sum of its proper divisors (74727163).

1821649157 is a wasteful number, since it uses less digits than its factorization.

1821649157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2212.

The product of its digits is 120960, while the sum is 44.

The square root of 1821649157 is about 42680.7820570336. The cubic root of 1821649157 is about 1221.2978120168.

The spelling of 1821649157 in words is "one billion, eight hundred twenty-one million, six hundred forty-nine thousand, one hundred fifty-seven".