55942921 has 2 divisors, whose sum is σ = 55942922. Its totient is φ = 55942920.

The previous prime is 55942919. The next prime is 55942949. The reversal of 55942921 is 12924955.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54597321 + 1345600 = 7389^2 + 1160^2 .

It is a cyclic number.

It is not a de Polignac number, because 55942921 - 2¹ = 55942919 is a prime.

It is a super-2 number, since 2×55942921² = 6259220820024482, which contains 22 as substring.

Together with 55942919, it forms a pair of twin primes.

It is the 7480-th Hogben number.

It is not a weakly prime, because it can be changed into another prime (55942951) by changing a digit.

It is a nontrivial repunit in base 7479.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27971460 + 27971461.

It is an arithmetic number, because the mean of its divisors is an integer number (27971461).

Almost surely, 2^55942921 is an apocalyptic number.

It is an amenable number.

55942921 is a deficient number, since it is larger than the sum of its proper divisors (1).

55942921 is an equidigital number, since it uses as much as digits as its factorization.

55942921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 37.

The square root of 55942921 is about 7479.5000501370. The cubic root of 55942921 is about 382.4562064148.

It can be divided in two parts, 5594 and 2921, that added together give a triangular number (8515 = T₁₃₀).

The spelling of 55942921 in words is "fifty-five million, nine hundred forty-two thousand, nine hundred twenty-one".