2145542021 has 16 divisors (see below), whose sum is σ = 2508105600. Its totient is φ = 1797355968.

The previous prime is 2145541999. The next prime is 2145542099. The reversal of 2145542021 is 1202455412.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2145542021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145542821) 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, 56435 + ... + 86463.

It is an arithmetic number, because the mean of its divisors is an integer number (156756600).

Almost surely, 2^2145542021 is an apocalyptic number.

It is an amenable number.

2145542021 is a deficient number, since it is larger than the sum of its proper divisors (362563579).

2145542021 is a wasteful number, since it uses less digits than its factorization.

2145542021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30268.

The product of its (nonzero) digits is 3200, while the sum is 26.

The square root of 2145542021 is about 46319.9959088945. The cubic root of 2145542021 is about 1289.7702094549.

Adding to 2145542021 its reverse (1202455412), we get a palindrome (3347997433).

The spelling of 2145542021 in words is "two billion, one hundred forty-five million, five hundred forty-two thousand, twenty-one".