53542157721 has 16 divisors (see below), whose sum is σ = 77216784960. Its totient is φ = 32805132480.

The previous prime is 53542157717. The next prime is 53542157759. The reversal of 53542157721 is 12775124535.

It is a happy number.

It is not a de Polignac number, because 53542157721 - 2² = 53542157717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (53542157701) 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, 2988615 + ... + 3006476.

It is an arithmetic number, because the mean of its divisors is an integer number (4826049060).

Almost surely, 2^53542157721 is an apocalyptic number.

It is an amenable number.

53542157721 is a deficient number, since it is larger than the sum of its proper divisors (23674627239).

53542157721 is a wasteful number, since it uses less digits than its factorization.

53542157721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5995336.

The product of its digits is 294000, while the sum is 42.

The spelling of 53542157721 in words is "fifty-three billion, five hundred forty-two million, one hundred fifty-seven thousand, seven hundred twenty-one".